You stand up from the sofa, the world does a slow tilt-a-whirl, your ears ring, and for a few seconds you’re genuinely worried you might faint. Then it clears and you feel silly for worrying. But if you’re wondering what to do if you feel dizzy when standing up, here’s the reassuring news: it’s usually harmless — and the less reassuring news: occasionally it isn’t. Knowing the difference matters.

The medical term is orthostatic (postural) hypotension: a drop in blood pressure when you stand. Gravity pulls blood downward; your body normally compensates in seconds by constricting vessels and quickening your pulse. When that compensation lags — because you’re dehydrated, overheated, on certain medications, or just got up too fast — your brain briefly gets less blood, and the room spins.

What to do in the moment

  1. Sit or lie back down immediately. Don’t try to power through — that’s how people faint and hit their heads. Sit with your head between your knees, or lie flat.
  2. Wait it out. Episodes typically pass in seconds to a couple of minutes as your circulation catches up.
  3. Drink water. Once steady, have a glass of water — dehydration is the most common fixable cause (see the signs of dehydration to check).
  4. Get up slowly next time. Sit on the edge of the bed for 30 seconds before standing in the morning — the highest-risk moment of the day.

Why it happens: the common causes

  • Dehydration. The number one cause — less fluid means less blood volume means a bigger drop on standing. Hot weather, illness, alcohol and not drinking enough all contribute.
  • Getting up too fast. Especially from lying down, after long sitting, or first thing in the morning.
  • Medications. Blood pressure drugs, diuretics, some antidepressants, and prostate medications commonly cause it. Never stop medication because of dizziness — talk to your GP or pharmacist about timing or alternatives.
  • Low blood sugar. Skipped meals plus standing quickly is a classic combination. If this pattern sounds familiar, read our guide on blood sugar warning signs — the two are often linked.
  • Prolonged standing or heat. Blood pools in the legs; heat dilates vessels. Queues at festivals, hot kitchens, long church services — all classic settings.
  • Anaemia. Low iron reduces oxygen delivery, making the brain more sensitive to pressure dips. Worth checking if you’re often tired as well as dizzy.
  • Age-related changes. Blood pressure regulation gets less snappy with age, which is why this is so common in older adults — and why it’s a fall risk worth taking seriously.

How to prevent it

  • Hydrate properly — 1.6–2 litres of fluid daily, more in heat or when active.
  • Rise in stages: lie → sit (30 seconds) → stand. Every time, until it’s habit.
  • Don’t skip meals, and go easy on alcohol — both destabilise blood pressure.
  • Compression stockings help if leg blood-pooling is the issue (knee-high, graduated — about £10–£20).
  • Counter-manoeuvres: tensing your leg and buttock muscles before standing, or crossing your legs while standing, physically squeezes blood upward. It looks odd; it works.
  • Review medications with your GP or pharmacist if dizziness started after a new prescription.
  • Check your blood pressure properly — including lying, sitting and standing readings if your GP suspects postural hypotension. Our guide to checking blood pressure at home accurately covers the technique.

Dizzy when standing up: when to get medical help

See your GP if episodes are frequent, worsening, cause actual fainting, or started after new medication. Seek urgent care if dizziness comes with chest pain, palpitations, shortness of breath, severe headache, slurred speech, weakness on one side, or fainting with injury — these suggest cardiac or neurological causes that need prompt assessment. The NHS page on dizziness and lightheadedness outlines when to seek help.

Dizziness on standing: the self-assessment questions

Before your appointment — or to decide whether you need one — run through these questions. Your answers tell a GP a great deal, and they often reveal a fixable cause.

  • When did it start, and was there a trigger? New medication (especially blood pressure drugs, diuretics, antidepressants), a recent illness with vomiting/diarrhoea, increased alcohol, or a change in diet? Drug-induced orthostatic dizziness is extremely common and often fixable with a timing or dose adjustment — never stop a prescribed drug without medical advice, but do flag the correlation.
  • How’s your fluid and salt intake? Chronically low fluid intake is the most underrated cause. The fix isn’t dramatic — an extra 500ml of water daily and not skipping meals. Very low-salt diets can contribute too; unless your doctor has restricted salt for a specific reason, normal salting is fine.
  • What time of day is worst? Mornings are classic (overnight dehydration, getting up fast). After big carbohydrate-heavy meals suggests postprandial hypotension — smaller, lower-carb meals help. After exercise points to dehydration or heat.
  • Any other symptoms? Palpitations with the dizziness (possible heart rhythm issue — get checked promptly). Headache, visual changes, weakness on one side (neurological — urgent). Fatigue, pale skin, heavy periods (anaemia — blood test). Just the dizziness alone, briefly, on standing (usually benign orthostatic hypotension).
  • Does anything help? If tensing your leg muscles, crossing your legs, or sitting back down resolves it within seconds, that’s textbook orthostatic hypotension — reassuring pattern, still worth mentioning to your GP.

The home experiments worth trying for two weeks: drink a large glass of water 15 minutes before the times dizziness usually strikes (mornings, post-lunch); rise in stages (sit on the bed edge for 30 seconds before standing); add a pinch more salt if your diet is very low-sodium; and do gentle calf raises through the day — the calf muscles are your “second heart” for pumping blood upward.

Keep a brief log: date, time, what you were doing, how long it lasted, what helped. Two weeks of this turns a vague “I get dizzy sometimes” into a pattern your GP can act on — and half the time, the pattern points to something simple.

Your takeaway: usually benign, always worth understanding

Feeling dizzy when standing up is usually simple postural hypotension — sit down, hydrate, rise slowly, and review medications with your GP if it’s recurrent. Treat frequent episodes, fainting, or dizziness with chest symptoms as medical, not mysterious. Most of the time, a glass of water and a slower morning routine fix it.