You stand up from your desk, get out of bed or rise from the sofa and suddenly feel lightheaded. Your vision may briefly darken, you might feel unsteady, or it can seem as though you are about to faint.
So, why do you feel dizzy when you stand up?
A brief spell of dizziness after standing can happen when your blood pressure temporarily falls as your body adjusts to the change in position. This is often described as postural hypotension or orthostatic hypotension.
An occasional head rush that passes quickly is not necessarily a sign that something is wrong. However, dizziness that keeps happening, lasts longer, causes fainting or appears alongside other symptoms should be assessed.
Possible causes include dehydration, low blood pressure, iron deficiency anaemia, medication and conditions that affect how the body regulates heart rate or blood pressure.
What Happens to Your Body When You Stand Up?
When you move from sitting or lying down to standing, gravity causes some blood to move towards your legs and lower body.
Your body normally responds almost immediately. Blood vessels tighten and your heart adjusts so that enough blood continues to reach your brain.
If that response is delayed or less effective, your blood pressure can temporarily fall. This may leave you feeling lightheaded, weak or as though you might faint. Some people also notice blurred or darker vision.
Sitting or lying down again will often help the sensation pass.
What Is Postural Hypotension?
Postural hypotension, also called orthostatic hypotension, is a drop in blood pressure that happens after standing up from sitting or lying down.
Symptoms can include lightheadedness, blurred vision, weakness, nausea, confusion, feeling faint or actually fainting.
Having naturally low blood pressure does not automatically mean there is a problem. It becomes more important to investigate when changing position repeatedly causes symptoms. A doctor may compare your blood pressure and pulse while lying or sitting with measurements taken after you stand.
What Causes Dizziness When Standing Up?
There is no single cause of postural dizziness. The pattern of your symptoms and any other health problems can help narrow down the possibilities.
Dehydration
Dehydration can reduce the amount of fluid circulating around the body, making it harder to maintain blood pressure when you stand.
It may happen because you have not been drinking enough, have exercised heavily, spent time in hot weather, or experienced vomiting or diarrhoea. Thirst, dark yellow urine, a dry mouth and urinating less often can also suggest dehydration.
Low Blood Pressure
The NHS defines low blood pressure as below 90/60mmHg. Some people naturally have lower readings without symptoms, but low blood pressure can cause dizziness, blurred vision or fainting. If symptoms repeatedly appear after standing, a GP may assess whether postural hypotension is contributing.
Iron Deficiency Anaemia
Iron deficiency anaemia can cause dizziness, particularly alongside persistent tiredness, shortness of breath, headaches, noticeable heartbeats or paler-than-usual skin.
Heavy periods are one possible cause, but there are others. Persistent or unexplained iron deficiency should be assessed so the underlying reason can be identified.
Medication
Some medicines can lower blood pressure or affect how well your body adjusts when you stand.
If dizziness began after starting a medicine or changing a dose, speak to a doctor or pharmacist. Do not stop prescribed medication without medical advice.
Blood Sugar Changes
Low blood sugar can cause dizziness, weakness, sweating, shaking and difficulty concentrating.
People with diabetes who experience recurring symptoms that could indicate low blood sugar should follow the advice from their healthcare team.
Heart Rate or Circulation Problems
Your heart and blood vessels help maintain blood flow to your brain when you change position.
Tell a doctor if dizziness occurs alongside palpitations, chest discomfort, breathlessness, reduced exercise tolerance or fainting, as these symptoms may affect which investigations are appropriate.
Is Dizziness the Same as Vertigo?
Not exactly. “Dizziness” can describe several different sensations, so being clear about what you feel can help a doctor assess the likely cause.
| Feeling | What it may feel like |
| Lightheadedness | Feeling faint, weak or as though you may pass out |
| Vertigo | Feeling as though you or your surroundings are spinning |
| Imbalance | Feeling unstable or unsteady while standing or walking |
| Postural dizziness | Lightheadedness triggered by standing or changing position |
If the room appears to spin, especially when you move your head or turn over in bed, the problem may be vertigo rather than a temporary fall in blood pressure.
Why Do I Get a Head Rush When I Stand Up?
“Head rush” is not a medical diagnosis, but it commonly describes a brief feeling of lightheadedness, altered vision or unsteadiness after standing quickly.
An occasional episode lasting only a few seconds may not be a cause for concern. Speak to a doctor if head rushes happen frequently, you need to hold onto something to avoid falling, you regularly experience visual changes or you have fainted.
Why Does My Vision Go Dark When I Stand Up?
Some people notice black spots, tunnel vision or temporary darkening of their vision after standing.
This may happen while your body adjusts to being upright. Your vision should normally return quickly.
Repeated or significant visual disturbance should be assessed, particularly if you faint, develop a severe headache or notice visual symptoms that do not disappear after sitting or lying down.
Why Am I Dizzy When I Get Out of Bed?
Moving straight from lying flat to standing makes getting out of bed a common time to notice postural dizziness.
Try sitting on the edge of the bed briefly before standing. If you feel dizzy, remain seated until the sensation passes.
Recurring morning dizziness should still be discussed with a healthcare professional, especially if changing position more slowly does not help.
Could Dizziness When Standing Be PoTS?
Postural tachycardia syndrome, or PoTS, can cause dizziness after standing and is different from postural hypotension.
With PoTS, the heart rate rises abnormally after moving upright. Other symptoms can include palpitations, near-fainting, tiredness, headaches, blurred vision and difficulty concentrating.
These symptoms do not automatically mean you have PoTS. A GP can assess whether further investigation is needed.
Is Feeling Dizzy When You Stand Up Normal?
Occasional, brief dizziness after standing quickly can happen. More important is how often it occurs, how severe it is and whether the pattern is changing.
Consider speaking to a doctor if the dizziness:
- keeps coming back
- lasts longer than a brief moment
- is becoming more frequent or severe
- affects normal activities
- causes falls, fainting or near-fainting
- happens alongside other unexplained symptoms
When Should You Seek Urgent Medical Help?
Most dizziness is not caused by a medical emergency, but certain symptoms require urgent attention.
Seek urgent medical help if dizziness occurs with new weakness or numbness, difficulty speaking, facial weakness, sudden significant changes to vision, loss of consciousness, a severe sudden headache, significant chest pain or severe breathing difficulties.
If you think someone may be having a stroke or another medical emergency, call 999.
What Can You Do If You Occasionally Feel Dizzy When Standing?
If episodes are occasional and there are no warning signs, a few simple measures may help:
- stand up gradually rather than moving suddenly
- move from lying to sitting before standing
- stay adequately hydrated
- sit or lie down if dizziness starts
- take extra care during hot weather or after illness
- avoid driving, climbing ladders or using machinery while dizzy
Do not stop prescribed medication because you think it may be responsible. Ask a doctor or pharmacist to review it instead.
How Does a GP Investigate Dizziness When Standing Up?
A GP will usually ask what the sensation feels like, how long it lasts, what triggers it and whether you experience visual changes, palpitations or fainting. Your medical history, medication and other symptoms can provide further clues.
Your blood pressure and pulse may be checked while lying, sitting and standing. Depending on your symptoms, a doctor may also consider a physical examination, an ECG or other investigations.
If you regularly experience unexplained dizziness, you can discuss your symptoms during a private GP appointment in London.
Can a Blood Test Find Out Why You Feel Dizzy?
Sometimes, but there is no single “dizziness blood test”.
Blood tests may be useful if your symptoms suggest an underlying cause. A full blood count and iron-related tests may help investigate anaemia, while other circumstances may warrant checks such as glucose, thyroid function or electrolytes.
Broadgate GP offers private blood tests in London where clinically appropriate, with testing selected according to your symptoms and medical history.
When Should You Speak to a GP?
Book a GP appointment if you regularly feel dizzy when you stand, your symptoms are becoming worse or you are concerned about what is causing them.
Mention associated symptoms such as persistent fatigue, shortness of breath, headaches, palpitations, hearing or vision changes, unusual bleeding or repeated fainting.
Depending on your assessment, a GP may recommend blood pressure measurements, blood tests, an ECG, treatment, monitoring or referral.
Recurring dizziness is a symptom rather than a diagnosis. Identifying the pattern, triggers and associated symptoms is the first step towards understanding what may be causing it.
If you would like your symptoms assessed privately, you can book an appointment with Broadgate GP.
Frequently Asked Questions
Why do I feel dizzy every time I stand up?
Repeated dizziness after standing can occur with postural hypotension. Dehydration, medication, anaemia and other conditions may also contribute. If it happens regularly, arrange a medical assessment.
Why do I get dizzy after sitting for a long time?
When you stand, your circulation needs to adjust quickly to keep enough blood flowing to your brain. If this response is delayed, you may briefly feel lightheaded.
Can dehydration make you dizzy when standing?
Yes. Dehydration can contribute to dizziness and lightheadedness, particularly after heavy sweating, hot weather, vomiting, diarrhoea or not drinking enough fluid.
Can anaemia cause dizziness when standing?
Yes. Anaemia can cause dizziness alongside tiredness, breathlessness, headaches and palpitations. Blood tests can help establish whether anaemia is present.
Should I worry if my vision goes black when I stand up?
A brief visual change can occur during postural lightheadedness. Frequent, severe or persistent visual disturbances should be assessed, particularly if you also faint or experience other neurological symptoms.
What doctor should I see for dizziness?
A GP is usually an appropriate starting point for recurring or unexplained dizziness. They can assess your symptoms, check your blood pressure and pulse, review medication and arrange further tests or referral if needed.
