A fast heart rate when you stand up

When you stand, gravity pulls blood down into your legs and abdomen. To keep blood flowing to your brain, your heart speeds up a little and your blood vessels tighten. In the first seconds, the heart rate often jumps and then settles.

For most healthy adults:

• Resting heart rate is usually between 60 and 100 beats per minute.
• When standing, it rises by about 10 to 20 beats per minute and stays fairly steady. A rise of less than 30 beats per minute is generally normal.

This is controlled by your autonomic nervous system, the "automatic" system that runs heart rate, blood pressure, and digestion without you thinking about it.

A heart rate over 100 beats per minute is called tachycardia. This can be completely normal during exercise, stress, or fever. It becomes worth checking when it happens simply from standing, again and again, or when your heart is fast even at rest.

Along with the fast heartbeat, people often notice:

• Palpitations (a racing, pounding, or fluttering heart)
• Feeling your heartbeat in your chest, neck, or ears
• Dizziness, lightheadedness, feeling close to faint or fainting
• Shortness of breath or chest discomfort when upright
• Shakiness or feeling jittery, a bit like anxiety
• Brain fog or trouble concentrating

A fast heart rate on standing is a sign, not a diagnosis on its own.

Everyday causes

• Not enough fluid. Less blood volume means the heart has to work harder.
• Heat, hot showers, or a big meal.
• Caffeine, nicotine, energy drinks, or alcohol.
• Fever or infection.
• Stress or anxiety.
• Poor fitness, especially after a long illness or time in bed.
• Pregnancy.

Medical causes worth checking

• POTS. Your heart rate rises by at least 30 beats per minute within 10 minutes of standing and stays high, without a clear drop in blood pressure. Read the POTS guide.
• Orthostatic hypotension. Your blood pressure drops when you stand, and the heart speeds up to make up for it.
• Inappropriate sinus tachycardia (IST). Your heart is fast most of the time, even at rest, not only when standing. Read the IST guide.
• Low iron or anaemia.
• An overactive thyroid.
• Medicines, for example some asthma inhalers, decongestants, ADHD medicines, and some antidepressants.
• Mast cell activation syndrome (MCAS), where episodes can include a racing heart along with flushing, itching, or stomach symptoms. Read the MCAS guide.

Heart rhythm problems

Some rhythm problems cause a very fast heartbeat that starts and stops suddenly, often in any position, lying down too. This is different from POTS, where the heart rate climbs gradually as you stand and settles when you lie down. Sudden, very fast episodes should always be checked with an ECG.

A racing heart when standing is one of the most common symptoms people report after COVID and other infections. For some it settles within weeks, as fitness and fluid balance return. For others it lasts for months. When it does, it can be a sign of POTS or another form of dysautonomia, where the automatic system that controls heart rate and blood pressure is out of balance.

A fast heart rate is not "just anxiety", even if it can feel like it. It can be measured, and there are treatments that help.

The key test is a stand test: your heart rate and blood pressure are measured while you lie down and then several times over 10 minutes of standing. This shows how much your heart rate rises and whether your blood pressure drops, which helps tell these conditions apart. It can be done in a clinic or at home with a blood pressure monitor and clear instructions.

Your doctor will usually also check an ECG (a recording of your heart's rhythm) and blood tests such as blood count, iron levels (ferritin) and thyroid function, and review your medicine, to rule out other causes.

While the cause is being sorted out, these are some things that can help most people with a fast heart rate on standing:

• Drink more fluid and stay well hydrated through the day.
• Consider more salt to help hold on to fluid (check first if you have high blood pressure, or heart or kidney disease).
• Cut back on stimulants like caffeine, nicotine and energy drinks.
• Keep a diary of your heart rate and symptoms. It helps you spot patterns and gives your doctor useful information.

If everyday measures are not enough, talk to a doctor about whether medicine could help. There is more detail on treatment in the POTS guide.

Call or go to the emergency department if you have:

• Fainting, especially during exertion or if it causes injury
• Chest pain or pressure
• A very fast or irregular heartbeat that does not settle when you lie down
• Severe shortness of breath
• Sudden weakness, numbness, or trouble speaking

Contact your clinic if:

• A fast heart rate on standing is new or getting worse
• Your heart is often fast when you stand, or even at rest
• You have fainted for the first time
• A family member has died suddenly at a young age or has a known heart rhythm problem