Experiencing a fast heartbeat or dizziness when standing up is a common bodily reaction to gravity, but frequent episodes can indicate dehydration, low blood pressure, anaemia, or conditions like POTS that require medical evaluation and simple lifestyle adjustments.

Experiencing a fast heartbeat or dizziness when standing up is a common bodily reaction to gravity, but frequent episodes can indicate dehydration, low blood pressure, anaemia, or conditions like POTS that require medical evaluation and simple lifestyle adjustments.

Experiencing a fast heartbeat or dizziness when standing up is a common bodily reaction to gravity, but frequent episodes can indicate dehydration, low blood pressure, anaemia, or conditions like POTS that require medical evaluation and simple lifestyle adjustments.

You get up from your chair, or out of bed, and your heart starts thumping. Maybe your head spins a little. Maybe your vision goes blurry for a second, or you feel so weak you wonder if you're about to faint. Almost everyone has had this at some point. Most of the time it's nothing to worry about. But if it keeps happening, or it feels intense, it deserves a proper look.

So what's going on in the body when you stand up?

Gravity does its job. The moment you stand, some of your blood sinks down into your legs. For a few seconds, less of it gets back to the heart, which means less goes up to the brain. The body notices this straight away. Your nervous system tells the heart to speed up and the blood vessels to squeeze a little tighter, so your blood pressure holds steady and your organs keep getting what they need. This happens every single time you change position, and you usually don't feel a thing. It becomes a problem when the heart races far more than it should, the symptoms hang around, or the body just can't keep blood pressure in check.

Why does the heart rate go too high?

There isn't one answer. A few common reasons:

  • Dehydration: If you haven't had enough water, or you've been sweating a lot, or you've had a fever, vomiting or loose motions, your body has less blood volume. The heart then beats faster to cover for it
  • Low blood pressure: For some people, blood pressure actually drops when they stand. Doctors call this orthostatic hypotension. You feel light-headed, weak, maybe a bit blurry, and it's most noticeable when you leap out of bed in the morning
  • Anaemia: When there aren't enough red blood cells or haemoglobin to carry oxygen, the heart tries to make up for it by working faster. Low iron is one reason, and it's quite common in women who have heavy periods
  • Being inactive for too long: If you've been sitting or lying around for weeks, your body gets out of practice at adjusting to posture changes. Then the heart has to work harder every time you get up.
  • Caffeine, stress and some medicines: Too many cups of tea or coffee, anxiety, bad sleep, certain medicines- any of these can bring on palpitations or a fast pulse. Tablets that affect blood pressure or fluid levels can do it too
  • Postural Orthostatic Tachycardia Syndrome (POTS): In some people, standing sets off a big rise in heart rate that doesn't settle. They also feel dizzy, tired, weak, find it hard to concentrate, or notice their heart pounding. POTS is a real condition of the autonomic nervous system, the part that runs things like heart rate and blood pressure without you thinking about it. But a fast heartbeat alone doesn't mean POTS. Other causes have to be checked and ruled out first

When should you be concerned?

If your heart rate goes up for a moment, comes back down soon, and you feel fine otherwise, that's likely normal. Don't ignore it, though, if it keeps repeating, starts getting in the way of your day, or your heart stays fast for a long time. Go and see a doctor if you also have dizziness that doesn't go away, tiredness that feels out of the ordinary, breathlessness, frequent near-fainting, or you notice you can't exercise like you used to. The doctor may check your pulse and blood pressure lying down and then standing, look at the medicines you're on, and ask for tests like a blood count, blood sugar, thyroid tests or an ECG. Chest pain, severe breathlessness, fainting while exerting yourself, or a racing heart followed by collapse is an emergency. Get to a hospital right away.

What can you do yourself?

If posture or mild dehydration is the cause, a few small habits can make a real difference. Don't jump up. Sit at the edge of the bed for a minute first. Drink enough water. Try not to stand in one spot for very long. Eat regular meals and keep moving every day, since that's good for your heart anyway.

One word of caution: don't add extra salt, start supplements or stop your regular medicines on your own. If you have a heart, kidney or blood pressure problem, please talk to your doctor first. Another useful thing is to keep a small note of when the episodes come, how long they last, what you felt, and what might have set them off. It helps the doctor see the pattern. And if the symptoms begin suddenly, get more frequent, or don't improve even after these changes, get yourself checked.

The bottom line

Often, a faster heartbeat when you stand is simply your body working against gravity to keep the blood moving. But if it's too much, lasts too long, or comes with other symptoms, the cause could be dehydration, low blood pressure, anaemia, a medicine, or something like POTS. It's important to tell the difference between a normal reaction and one that keeps coming back. Please don't just put repeated episodes down to weakness or stress. Find out what's causing them. Once you know, it's far easier to treat, and you can avoid problems that didn't have to happen.

The author is the director of cardiology at the CK Birla Hospital®, Delhi. 

 

The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK. 

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