Page last reviewed: 13/07/2011
Dizziness is a common symptom that's not usually a sign of anything serious, but should be checked out by a doctor.
The term 'dizziness' means different things to different people: some use it to describe feeling lightheaded or off balance, while others use it to describe a feeling that their surroundings are spinning.
Because the symptom is quite vague and can be caused by a wide range of factors, it may not always be easy to identify the underlying cause of dizziness.
This page explains what you should do if you feel dizzy for no apparent reason, and outlines the most common causes.
Seeing your GP
Your GP will first want to establish exactly what you mean by dizziness, and check that you are not actually describing vertigo, a severe type of dizziness where you feel that your surroundings are spinning or moving.
They'll want to know:
- whether the dizziness started for no apparent reason, or if it followed an illness
- whether you have repeated episodes of dizziness and, if so, when you tend to experience these
- how long the dizziness lasts
Dizziness can sometimes be caused by an ear condition. A simple way for your GP to distinguish between ear-related dizziness and dizziness due to other causes is to ask if it occurs only when you are upright, or even when you're lying down:
- If the dizziness only happens when you're upright, the cause is probably not related to the ear.
- If the dizziness sometimes happens when you're lying down, the cause is usually an ear condition.
It's a good idea to keep a diary of your dizziness (see box, above left), recording when and where you experience the problem, and bring this with you to your GP appointment.
If you are taking prescription medicine, your GP will probably review this to check your dizziness is not one of the side effects and, if necessary, try you on a different medication instead. You may be referred to a specialist for further tests and investigations.
Common causes of dizziness
The most common causes of dizziness are outlined below:
- A viral illness that affects the ear - this can cause a severe form of dizziness called vertigo
- Migraine (dizziness may come on before or after the headache)
- Stress or anxiety, especially if you tend to hyperventilate (over-breathe)
- A low blood sugar level, which is usually seen in people with diabetes
- A sudden fall in blood pressure when you suddenly sit or stand up, which goes away after lying down - this is know as postural hypotension and is more common in older people
- Decreased blood flow in the back of the brain, called vertebrobasilar insufficiency - the blood vessels leading to the brain from the heart may be blocked (known as atherosclerosis)
You can click on the above links for more information on these conditions.
Less common causes of dizziness
- Any severe illness or disease that affects the whole body
- Recreational drugs or excess alcohol (either binge drinking, or long-term alcohol misuse)
- Certain types of prescription medicine, such as antidepressants or blood pressure medication
- A heart rhythm problem, such as atrial fibrillation (a fast, irregular heartbeat)
- Carbon monoxide poisoning
Click on the above links for more information on these conditions.
Keeping a dizziness diary
Try to record the following information every time you experience dizziness:
- What time the attack occurred
- What you were doing at the time
- How long the dizziness lasted
- Whether you had any other symptoms, such as fainting
- How severe it was – for example, was it bad enough for you to stay in bed?