Dizzy with heart racing when standing up
See a doctor about this one
See a doctor about this one. It is a symptom that needs a cause found, and no remedy on this site is a substitute for that.
You get up from a chair or bed, and the room tilts. Your heart starts to pound or race. You may grab a wall, sit back down, or wait for it to pass.
When you stand, gravity pulls blood down into your legs. Your body should squeeze the blood vessels and steady your pulse. If that response is slow or off, your brain gets less blood for a moment, and your heart speeds up to catch up.
Mast cells are immune cells that sit in the walls of your blood vessels. When they release their chemicals, vessels can widen and blood can pool low in the body. Heat, a hot shower, a big meal, too little fluid or salt, a poor night's sleep, or long hours in bed can all make the drop worse.
When to see someone
Call emergency help if you faint, have chest pain, or cannot breathe well. Hives, a swollen tongue, or swelling of the lips along with the dizziness also need help right away.
See your doctor if you fall or hit your head, or if your pulse stays fast and pounding after you sit down. Book a visit too if this is new, getting worse, or started with a new medicine.
How to read the grades below
Below is a list of remedies that people use for mast cell problems. Each one carries a grade that shows how strong the research behind it is, not how well it will do for you. Read the grades first, and talk with your doctor or pharmacist before you try anything on the list.
What matters most to you right now with your mast cell activation syndrome?
Calm my body's overreactions at the source (steady my mast cells over time)
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Flavonoid often paired with quercetin
- Why it may be relevant
- You are looking to calm mast-cell overactivity, and luteolin is a flavonoid commonly combined with quercetin to support a steadier histamine response.
- Why try it
- Traditionally used alongside other flavonoids to support calmer mast-cell activity.
- Dose or use
- Usually taken as a supplement, often combined with quercetin; follow the product's label for dosing.
- Time to results
- Typically weeks of steady use before changes are noticeable.
- Key study
- Traditionally used for mast-cell and histamine support; this specific use has not been confirmed in controlled clinical trials.
- Caution
- Little safety data exists in pregnancy or with medications; introduce one new supplement at a time and check with your doctor.
Not yet assessed· We have not reviewed the literature for this one (Evidence grade not assigned · Traditional use recognised)Recognised traditional use Blend formulated for mast-cell support
- Why it may be relevant
- You want to calm mast-cell reactions, and this is a supplement blend formulated specifically for mast-cell support.
- Why try it
- Traditionally used as a combination product aimed at supporting a calmer mast-cell response.
- Dose or use
- Follow the product label; blends typically combine flavonoids and supportive nutrients.
- Time to results
- Usually weeks of consistent use.
- Key study
- A combination product used traditionally for mast-cell support; it has not been evaluated in controlled clinical trials.
- Caution
- Ingredients vary by product, so review the full label for allergens and interactions and check with your doctor before starting.
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Body-made compound that dampens mast cells
- Why it may be relevant
- You want to settle mast-cell overactivity, and PEA is a compound your body makes that helps down-modulate mast cells and calm inflammatory signaling.
- Why try it
- Its documented mechanism works partly by inhibiting mast cells, and it has human evidence for nerve and inflammatory pain.
- Dose or use
- Commonly taken as 300 to 600 mg once or twice daily with food.
- Time to results
- Often a few weeks of daily use.
- Key study
- Human studies support PEA for nerve and inflammatory pain through mast-cell modulation; its use specifically for MCAS has not been confirmed in controlled clinical trials.
- Caution
- Generally well tolerated, but safety in pregnancy is not established. Talk with your doctor if you take other medications.
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Flavonoid that helps calm mast cells
- Why it may be relevant
- You want to calm overactive mast cells, and quercetin is the most-studied natural flavonoid for steadying mast cells and easing histamine release.
- Why try it
- Traditionally used to support a calmer histamine response; its library profile lists allergic reactions and chronic inflammation among its uses.
- Dose or use
- Commonly taken as 500 mg once or twice daily with food; many people pair it with vitamin C.
- Time to results
- Often several weeks of consistent use before reactions feel steadier.
- Key study
- Traditionally used to support mast-cell and histamine balance; this specific use in MCAS has not been confirmed in controlled clinical trials.
- Caution
- May interact with blood thinners and some antibiotics, and very high doses can affect kidney function. Check with your doctor if you take medications.
Check for underlying nutrient gaps that could be making me more reactive
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Vitamin that supports histamine breakdown
- Why it may be relevant
- You want to ease allergy-type symptoms, and vitamin C acts as a mild natural antihistamine that supports your body's breakdown of histamine.
- Why try it
- Traditionally used to support histamine clearance and immune balance; its library profile lists inflammation and immune support.
- Dose or use
- Commonly taken as 500 to 1000 mg daily, split through the day; higher doses can loosen stools.
- Time to results
- Often a couple of weeks of steady use.
- Key study
- Traditionally used as a natural antihistamine; this specific use in MCAS has not been confirmed in controlled clinical trials.
- Caution
- High doses may cause digestive upset and can raise kidney-stone risk in prone individuals. Check with your doctor if you have kidney concerns.
Vitamin C Deficiency
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional stapleLow vitamin C raises histamine load
- Why it may be relevant
- You want to address underlying gaps, and vitamin C helps break down histamine, so low levels can add to your histamine burden.
- Why try it
- Restoring adequate vitamin C is a simple, correctable step that supports histamine clearance.
- Dose or use
- Ensure adequate dietary vitamin C from fruits and vegetables, and supplement if your intake is low.
- Time to results
- Tissue levels restore within weeks of adequate intake.
- Key study
- Vitamin C supports histamine breakdown; a deficiency's specific role in MCAS has not been confirmed in controlled clinical trials.
- Caution
- Very high supplemental doses can cause digestive upset, though food sources are well tolerated.
Vitamin D Deficiency
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional stapleLow vitamin D can worsen reactivity
- Why it may be relevant
- You want to address underlying gaps, and low vitamin D is linked to heightened allergic and mast-cell reactivity, so it is worth checking.
- Why try it
- Correcting a vitamin D deficiency is a plausible upstream lever for calmer immune and mast-cell balance.
- Dose or use
- Ask your doctor for a blood test and supplement to reach a healthy level if you are low.
- Time to results
- Levels typically rebuild over 2 to 3 months of supplementation.
- Key study
- Low vitamin D is associated with greater allergic and mast-cell reactivity; a direct benefit in MCAS has not been confirmed in controlled clinical trials.
- Caution
- Too much vitamin D can raise blood calcium, so dose based on testing rather than guesswork.
Figure out and reduce my food triggers (lower my histamine load from what I eat)
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Eating pattern that lowers histamine load
- Why it may be relevant
- You want to adjust your diet, and a low-histamine eating pattern reduces the food-based histamine triggers that can drive MCAS symptoms.
- Why try it
- Widely used as a first-line, food-based approach to lower histamine load and to help you identify your own trigger foods.
- Dose or use
- Favor fresh, freshly cooked foods and limit aged, fermented, cured, and leftover items; an elimination-and-reintroduction approach helps pinpoint triggers.
- Time to results
- Some people notice differences within days to a couple of weeks.
- Key study
- Commonly recommended as first-line management for histamine-related symptoms; benefit for MCAS has not been confirmed in controlled clinical trials.
- Caution
- It can be restrictive, so work with a dietitian to avoid nutrient gaps, especially if used long term.
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Vitamin that supports histamine breakdown
- Why it may be relevant
- You want to ease allergy-type symptoms, and vitamin C acts as a mild natural antihistamine that supports your body's breakdown of histamine.
- Why try it
- Traditionally used to support histamine clearance and immune balance; its library profile lists inflammation and immune support.
- Dose or use
- Commonly taken as 500 to 1000 mg daily, split through the day; higher doses can loosen stools.
- Time to results
- Often a couple of weeks of steady use.
- Key study
- Traditionally used as a natural antihistamine; this specific use in MCAS has not been confirmed in controlled clinical trials.
- Caution
- High doses may cause digestive upset and can raise kidney-stone risk in prone individuals. Check with your doctor if you have kidney concerns.
Vitamin C Deficiency
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional stapleLow vitamin C raises histamine load
- Why it may be relevant
- You want to address underlying gaps, and vitamin C helps break down histamine, so low levels can add to your histamine burden.
- Why try it
- Restoring adequate vitamin C is a simple, correctable step that supports histamine clearance.
- Dose or use
- Ensure adequate dietary vitamin C from fruits and vegetables, and supplement if your intake is low.
- Time to results
- Tissue levels restore within weeks of adequate intake.
- Key study
- Vitamin C supports histamine breakdown; a deficiency's specific role in MCAS has not been confirmed in controlled clinical trials.
- Caution
- Very high supplemental doses can cause digestive upset, though food sources are well tolerated.
Get through flares — itching, hives, flushing, or congestion — with in-the-moment relief
LI11 (Quchi) - Large Intestine 11
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional stapleAcupressure point for itching and hives
- Why it may be relevant
- You want relief from allergy-type skin symptoms, and LI11 is the classic acupressure point used for itching, hives, and heat-type skin reactions.
- Why try it
- Traditionally used to cool inflammatory skin reactions and calm itching during flares.
- Dose or use
- Find the point at the outer end of the elbow crease and press firmly for 1 to 2 minutes on each arm.
- Time to results
- May bring in-the-moment relief; use regularly over weeks for ongoing support.
- Key study
- A traditional acupressure point used for itching and skin reactions; not evaluated for MCAS in controlled clinical trials.
- Caution
- Avoid pressing over broken or irritated skin; acupressure supports comfort but does not replace medical care for severe reactions.
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Traditional herbal antihistamine
- Why it may be relevant
- You want to ease allergy-type symptoms, and stinging nettle is a traditional herbal antihistamine used for sneezing, itching, and hay-fever-type reactions.
- Why try it
- Its library profile marks allergic rhinitis (sneezing and itching) as an effective use, and it is a long-standing remedy for histamine-driven symptoms.
- Dose or use
- Often taken as a freeze-dried leaf capsule (about 300 to 600 mg) during allergy flares, or brewed as a tea.
- Time to results
- Some people notice relief within days during a flare.
- Key study
- Traditionally used for allergic, histamine-driven symptoms; its use specifically in MCAS has not been confirmed in controlled clinical trials.
- Caution
- It can act as a diuretic and may interact with blood-pressure and diabetes medications. Check with your doctor if you take these.
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Vitamin that supports histamine breakdown
- Why it may be relevant
- You want to ease allergy-type symptoms, and vitamin C acts as a mild natural antihistamine that supports your body's breakdown of histamine.
- Why try it
- Traditionally used to support histamine clearance and immune balance; its library profile lists inflammation and immune support.
- Dose or use
- Commonly taken as 500 to 1000 mg daily, split through the day; higher doses can loosen stools.
- Time to results
- Often a couple of weeks of steady use.
- Key study
- Traditionally used as a natural antihistamine; this specific use in MCAS has not been confirmed in controlled clinical trials.
- Caution
- High doses may cause digestive upset and can raise kidney-stone risk in prone individuals. Check with your doctor if you have kidney concerns.
LI4 (Hegu) - Large Intestine 4
Not yet assessed· We have not reviewed the literature for this one (Evidence grade not assigned · Traditional use recognised)Recognised traditional useVersatile point for allergy-type symptoms
- Why it may be relevant
- You want relief from allergy-type symptoms, and LI4 is a widely used acupressure point traditionally paired with LI11 for facial, allergic, and general symptom relief.
- Why try it
- Traditionally used for headaches and allergic-type complaints, and a simple self-care option during flares.
- Dose or use
- Find the point in the webbing between thumb and index finger and press firmly for 1 to 2 minutes on each hand.
- Time to results
- Often used for in-the-moment relief.
- Key study
- A traditional acupressure point used for allergic and general symptom relief; not evaluated for MCAS in controlled clinical trials.
- Caution
- Avoid during pregnancy, as this point is traditionally avoided then. It is not a substitute for medical care in severe reactions.
What kind of approach fits you best?
I'd rather start with food — what I eat and the nutrients I may be missing
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Eating pattern that lowers histamine load
- Why it may be relevant
- You want to adjust your diet, and a low-histamine eating pattern reduces the food-based histamine triggers that can drive MCAS symptoms.
- Why try it
- Widely used as a first-line, food-based approach to lower histamine load and to help you identify your own trigger foods.
- Dose or use
- Favor fresh, freshly cooked foods and limit aged, fermented, cured, and leftover items; an elimination-and-reintroduction approach helps pinpoint triggers.
- Time to results
- Some people notice differences within days to a couple of weeks.
- Key study
- Commonly recommended as first-line management for histamine-related symptoms; benefit for MCAS has not been confirmed in controlled clinical trials.
- Caution
- It can be restrictive, so work with a dietitian to avoid nutrient gaps, especially if used long term.
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Vitamin that supports histamine breakdown
- Why it may be relevant
- You want to ease allergy-type symptoms, and vitamin C acts as a mild natural antihistamine that supports your body's breakdown of histamine.
- Why try it
- Traditionally used to support histamine clearance and immune balance; its library profile lists inflammation and immune support.
- Dose or use
- Commonly taken as 500 to 1000 mg daily, split through the day; higher doses can loosen stools.
- Time to results
- Often a couple of weeks of steady use.
- Key study
- Traditionally used as a natural antihistamine; this specific use in MCAS has not been confirmed in controlled clinical trials.
- Caution
- High doses may cause digestive upset and can raise kidney-stone risk in prone individuals. Check with your doctor if you have kidney concerns.
Vitamin C Deficiency
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional stapleLow vitamin C raises histamine load
- Why it may be relevant
- You want to address underlying gaps, and vitamin C helps break down histamine, so low levels can add to your histamine burden.
- Why try it
- Restoring adequate vitamin C is a simple, correctable step that supports histamine clearance.
- Dose or use
- Ensure adequate dietary vitamin C from fruits and vegetables, and supplement if your intake is low.
- Time to results
- Tissue levels restore within weeks of adequate intake.
- Key study
- Vitamin C supports histamine breakdown; a deficiency's specific role in MCAS has not been confirmed in controlled clinical trials.
- Caution
- Very high supplemental doses can cause digestive upset, though food sources are well tolerated.
Vitamin D Deficiency
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional stapleLow vitamin D can worsen reactivity
- Why it may be relevant
- You want to address underlying gaps, and low vitamin D is linked to heightened allergic and mast-cell reactivity, so it is worth checking.
- Why try it
- Correcting a vitamin D deficiency is a plausible upstream lever for calmer immune and mast-cell balance.
- Dose or use
- Ask your doctor for a blood test and supplement to reach a healthy level if you are low.
- Time to results
- Levels typically rebuild over 2 to 3 months of supplementation.
- Key study
- Low vitamin D is associated with greater allergic and mast-cell reactivity; a direct benefit in MCAS has not been confirmed in controlled clinical trials.
- Caution
- Too much vitamin D can raise blood calcium, so dose based on testing rather than guesswork.
I'd rather take targeted supplements or herbs that calm histamine and mast cells
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Flavonoid often paired with quercetin
- Why it may be relevant
- You are looking to calm mast-cell overactivity, and luteolin is a flavonoid commonly combined with quercetin to support a steadier histamine response.
- Why try it
- Traditionally used alongside other flavonoids to support calmer mast-cell activity.
- Dose or use
- Usually taken as a supplement, often combined with quercetin; follow the product's label for dosing.
- Time to results
- Typically weeks of steady use before changes are noticeable.
- Key study
- Traditionally used for mast-cell and histamine support; this specific use has not been confirmed in controlled clinical trials.
- Caution
- Little safety data exists in pregnancy or with medications; introduce one new supplement at a time and check with your doctor.
Not yet assessed· We have not reviewed the literature for this one (Evidence grade not assigned · Traditional use recognised)Recognised traditional use Blend formulated for mast-cell support
- Why it may be relevant
- You want to calm mast-cell reactions, and this is a supplement blend formulated specifically for mast-cell support.
- Why try it
- Traditionally used as a combination product aimed at supporting a calmer mast-cell response.
- Dose or use
- Follow the product label; blends typically combine flavonoids and supportive nutrients.
- Time to results
- Usually weeks of consistent use.
- Key study
- A combination product used traditionally for mast-cell support; it has not been evaluated in controlled clinical trials.
- Caution
- Ingredients vary by product, so review the full label for allergens and interactions and check with your doctor before starting.
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Body-made compound that dampens mast cells
- Why it may be relevant
- You want to settle mast-cell overactivity, and PEA is a compound your body makes that helps down-modulate mast cells and calm inflammatory signaling.
- Why try it
- Its documented mechanism works partly by inhibiting mast cells, and it has human evidence for nerve and inflammatory pain.
- Dose or use
- Commonly taken as 300 to 600 mg once or twice daily with food.
- Time to results
- Often a few weeks of daily use.
- Key study
- Human studies support PEA for nerve and inflammatory pain through mast-cell modulation; its use specifically for MCAS has not been confirmed in controlled clinical trials.
- Caution
- Generally well tolerated, but safety in pregnancy is not established. Talk with your doctor if you take other medications.
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Flavonoid that helps calm mast cells
- Why it may be relevant
- You want to calm overactive mast cells, and quercetin is the most-studied natural flavonoid for steadying mast cells and easing histamine release.
- Why try it
- Traditionally used to support a calmer histamine response; its library profile lists allergic reactions and chronic inflammation among its uses.
- Dose or use
- Commonly taken as 500 mg once or twice daily with food; many people pair it with vitamin C.
- Time to results
- Often several weeks of consistent use before reactions feel steadier.
- Key study
- Traditionally used to support mast-cell and histamine balance; this specific use in MCAS has not been confirmed in controlled clinical trials.
- Caution
- May interact with blood thinners and some antibiotics, and very high doses can affect kidney function. Check with your doctor if you take medications.
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Traditional herbal antihistamine
- Why it may be relevant
- You want to ease allergy-type symptoms, and stinging nettle is a traditional herbal antihistamine used for sneezing, itching, and hay-fever-type reactions.
- Why try it
- Its library profile marks allergic rhinitis (sneezing and itching) as an effective use, and it is a long-standing remedy for histamine-driven symptoms.
- Dose or use
- Often taken as a freeze-dried leaf capsule (about 300 to 600 mg) during allergy flares, or brewed as a tea.
- Time to results
- Some people notice relief within days during a flare.
- Key study
- Traditionally used for allergic, histamine-driven symptoms; its use specifically in MCAS has not been confirmed in controlled clinical trials.
- Caution
- It can act as a diuretic and may interact with blood-pressure and diabetes medications. Check with your doctor if you take these.
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional staple Vitamin that supports histamine breakdown
- Why it may be relevant
- You want to ease allergy-type symptoms, and vitamin C acts as a mild natural antihistamine that supports your body's breakdown of histamine.
- Why try it
- Traditionally used to support histamine clearance and immune balance; its library profile lists inflammation and immune support.
- Dose or use
- Commonly taken as 500 to 1000 mg daily, split through the day; higher doses can loosen stools.
- Time to results
- Often a couple of weeks of steady use.
- Key study
- Traditionally used as a natural antihistamine; this specific use in MCAS has not been confirmed in controlled clinical trials.
- Caution
- High doses may cause digestive upset and can raise kidney-stone risk in prone individuals. Check with your doctor if you have kidney concerns.
I'd rather use simple hands-on techniques I can do anywhere, pill-free
LI11 (Quchi) - Large Intestine 11
Centuries of traditional use· Human evidence not yet assessed (Evidence grade not assigned · Traditional use long-standing)Long-standing traditional stapleAcupressure point for itching and hives
- Why it may be relevant
- You want relief from allergy-type skin symptoms, and LI11 is the classic acupressure point used for itching, hives, and heat-type skin reactions.
- Why try it
- Traditionally used to cool inflammatory skin reactions and calm itching during flares.
- Dose or use
- Find the point at the outer end of the elbow crease and press firmly for 1 to 2 minutes on each arm.
- Time to results
- May bring in-the-moment relief; use regularly over weeks for ongoing support.
- Key study
- A traditional acupressure point used for itching and skin reactions; not evaluated for MCAS in controlled clinical trials.
- Caution
- Avoid pressing over broken or irritated skin; acupressure supports comfort but does not replace medical care for severe reactions.
LI4 (Hegu) - Large Intestine 4
Not yet assessed· We have not reviewed the literature for this one (Evidence grade not assigned · Traditional use recognised)Recognised traditional useVersatile point for allergy-type symptoms
- Why it may be relevant
- You want relief from allergy-type symptoms, and LI4 is a widely used acupressure point traditionally paired with LI11 for facial, allergic, and general symptom relief.
- Why try it
- Traditionally used for headaches and allergic-type complaints, and a simple self-care option during flares.
- Dose or use
- Find the point in the webbing between thumb and index finger and press firmly for 1 to 2 minutes on each hand.
- Time to results
- Often used for in-the-moment relief.
- Key study
- A traditional acupressure point used for allergic and general symptom relief; not evaluated for MCAS in controlled clinical trials.
- Caution
- Avoid during pregnancy, as this point is traditionally avoided then. It is not a substitute for medical care in severe reactions.
Evidence grades describe the strength of published research for Mast Cell Activation Syndrome, not a promise of results. Nothing here is medical advice — talk to your clinician before starting anything, especially alongside prescription medication.
Other ways people describe this
Same underlying problem, different words.
Remedies people try for this
Remedies recommended for the same conditions. Evidence grades are shown on each page.
See your options in the app
See the natural options for Dizzy with heart racing when standing up and track what you try.