Dizziness

People use the word "dizziness" for several quite different sensations, and which one is meant decides everything: which doctor to see, what to check and how urgent it is. If the room spins, or you feel yourself being tipped and pulled sideways, that is vertigo and it has a page of its own. This page is about the other kinds: light-headedness and the feeling that you are about to faint, when your vision darkens and your legs go; the "empty", floating head; and unsteadiness, where your head is perfectly clear but your walking is not. These sensations have their own causes, and looking for them in the inner ear is a waste of time.

Light-headedness before a faint: blood pressure, heart, blood

The commonest mechanism is that for a few seconds the brain is not getting enough blood. The description is always recognisable: vision went dark, ears rang, a cold sweat came, the legs turned to cotton wool, you had to sit down at once. Sitting or lying down, it passes in a minute or two.

What usually lies behind it:

• Blood pressure dropping on standing. You get up from the bed or the table and it swims. This is orthostatic hypotension, and in older people it is close to being the leading cause of light-headedness and of falls. Dehydration, heat, a hot bath, alcohol, a heavy meal and time spent in bed all make it worse.
• The ordinary faint and its warnings. A stuffy room, long standing, the sight of blood, pain, coughing, straining on the toilet. This is a reflex response of the blood vessels and heart rate, and in itself it is not dangerous; falling onto a tiled floor is.
• Heart rhythm disturbances. These are suggested by light-headedness that arrives out of nowhere, with no warning and no relation to posture, especially with palpitations, an irregular beat or chest pain, and all the more so if the person has already blacked out.
• Anaemia. Weakness building up gradually, breathlessness on ordinary exertion, pallor, light-headedness on the slightest effort. In women with heavy periods and in people with hidden blood loss from the bowel this is the commonest finding.
• Lack of fluid and salt after diarrhoea, vomiting or heat, and while taking diuretics.
• Low blood sugar. Trembling, sweating, hunger, irritability, light-headedness; in people with diabetes, in connection with insulin or glucose-lowering tablets. In someone without diabetes such episodes are uncommon and call for investigation rather than a diet.

One distinction is worth holding on to: light-headedness that comes only on standing and light-headedness that arrives at rest are two different signals. The first is nearly always about blood pressure and fluid; the second makes you think about the heart.

Look in the medicine cabinet before the head

In someone over sixty-five the cause of dizziness is found in the list of medicines far more often than on a scan. Dizziness is one of the most common side effects there is, particularly with drugs that have been taken for years and that nobody connects with the complaint.

• blood pressure medicines, especially after a dose increase or the addition of a second drug;
• diuretics;
• drugs that relax blood vessels, and those used for an enlarged prostate — they lower standing blood pressure noticeably;
• antidepressants, antipsychotics, anti-anxiety medicines and sleeping tablets;
• opioid painkillers;
• older antihistamines and travel sickness remedies;
• insulin and diabetes tablets, through low blood sugar;
• certain antibiotics and diuretics that damage the inner ear — here the dizziness lasts and does not settle at rest.

The longer the list, the likelier the answer is in it. Nothing should be stopped on your own initiative: coming off a blood pressure drug or an antidepressant abruptly is dangerous in itself. The right move is to bring every box to a doctor and ask for the regimen to be reviewed.

When the head "floats" and the body is fine

There is a sensation that words fit badly: the head feels like cotton wool, everything has moved slightly further away, the floor feels soft, and yet nothing is spinning and the person is not in fact about to fall. These episodes turn up in supermarkets, on the underground, in queues, in meetings — wherever you cannot easily leave.

Behind it there is usually anxiety and the fast shallow breathing that goes with it. Without noticing, you breathe more often, the carbon dioxide level in the blood falls, the brain's blood vessels narrow, and light-headedness follows. Hyperventilation gives itself away through tingling in the fingers and around the mouth, a feeling of not getting enough air despite breathing deeply, tightness in the chest, palpitations, and a fear of fainting that almost never actually happens.

This is not "made-up" dizziness: the sensation is real and it can genuinely narrow a life. But it is not treated with circulation drugs; it is treated by working on the anxiety, with breathing techniques and by returning gradually to the situations the person has started to avoid. With one important caveat: it can only be put down to nerves once blood pressure, anaemia, heart rhythm and medicines have been ruled out — all the more so because anxiety sits perfectly happily alongside any of them.

When the trouble is balance on your feet

The third sensation under the same word is unsteadiness. The head is clear, nothing spins or darkens, but walking has become uncertain, it is worse in the dark and in narrow corridors, and you find yourself reaching for the wall. This is not about the ear or blood pressure but about balance as a whole, which rests on three supports: vision, sensation in the feet, and the balance organ. Two of them weakening is enough to send a person sideways.

• Damage to the nerves of the legs from diabetes, vitamin B12 deficiency, chemotherapy or alcohol: the feet go numb, burn or feel like someone else's, and the brain stops getting accurate information about where the floor is.
• Vision: new varifocals, an out-of-date prescription, cataracts, recent eye surgery.
• Parkinson's disease and other movement disorders: small steps, difficulty setting off, the trunk leaning forward.
• The aftermath of a stroke, changes in the cerebellum, and hydrocephalus in older people, where an unsteady gait comes with failing memory and urinary urgency.
• Joints and muscles: hip weakness, knee pain and foot deformities change the way a person walks, and it is felt as dizziness.

Unsteadiness in an older person is not a minor matter: a fall with a fracture changes a life more than the cause of the wobble ever would. So what counts here is not only the diagnosis but the very practical: an eye test, shoes that hold the heel, grab rails in the bathroom, a dim light in the hallway, cables and rugs cleared away, and exercises for balance and leg strength.

When the cause is the brainstem, not the blood pressure

Dizziness can be the first and almost only symptom of a stroke at the back of the brain, where the cerebellum and the brainstem sit. What separates it from harmless light-headedness is not the character of the dizziness but what comes with it.

Call an ambulance (the single European number is 112) if dizziness or light-headedness comes with any of the following:

• objects start to double, an eyelid drops, part of the field of vision goes missing;
• speech turns mushy, words come with difficulty, swallowing brings on choking;
• an arm, a leg or one side of the face goes weak or numb — the familiar picture of the drooping face and the arm that will not lift; but only some strokes start that way, and its absence cancels nothing;
• a sudden severe headache unlike previous ones, particularly with neck pain or after a sharp turn of the head;
• the person cannot stay on their feet even when someone holds them up;
• loss of consciousness, especially during exertion or while lying down;
• chest pain, marked breathlessness, a very fast or very slow pulse;
• light-headedness alongside black stools, vomiting blood or heavy bleeding.

You should also take seriously severe dizziness appearing for the first time in someone over sixty, or in anyone with high blood pressure, diabetes, atrial fibrillation, a smoking history or a previous stroke. In that situation "my blood pressure just dropped" cannot be assumed until a vascular cause has been excluded.

What you can do yourself

While the cause is unclear, it makes sense to cut both the risk of falling and the frequency of the episodes.

• Get up in two stages: sit on the edge of the bed first, stay there for half a minute, move your feet, and only then stand.
• If light-headedness has already come on, sit or lie down immediately and raise your legs — that is the fastest way to get blood back to the head. Standing and "riding it out" is dangerous.
• Drink enough, especially in hot weather, with diarrhoea and while taking diuretics.
• Avoid standing still for long spells, very hot baths and saunas, and heavy meals with alcohol.
• Keep a short diary: when it comes, in what position, how long it lasts, what the heart is doing. A fortnight of notes is worth several tests.
• If you have a blood pressure monitor at home, measure lying down and then one minute and three minutes after standing, recording the pulse too. That is precisely the measurement most often skipped.
• While the episodes are unpredictable, keep off the road, off ladders and away from machinery, and do not swim out without company. When you can take the wheel again is the doctor's call: the requirements differ from country to country.

What happens at the appointment

Almost everything here is decided by what you describe. The doctor will ask you to put the sensation in your own words, avoiding the word "dizziness" as far as you can, and will establish in what position it starts, how long it lasts, what the pulse and the vision do, what you take and what has changed in your treatment over recent months.

The examination almost always includes blood pressure and pulse lying and standing, an assessment of gait and balance, sensation in the legs, a brief neurological examination and a look in the ears. Blood tests usually mean a full blood count, glucose in mmol/L, electrolytes, kidney and thyroid function, and sometimes iron and vitamin B12. If a rhythm problem is suspected, an electrocardiogram and a whole-day rhythm recording are arranged, because the short tracing in the consulting room often shows nothing.

Scanning the head is not needed by everyone and is arranged when there are signs pointing to the brain. One detail is worth knowing here: a CT scan shows the back of the brain badly, so a normal result there does not cancel a stroke; where the suspicion is serious, an MRI is what is required.

Online consultation

Almost all the work on this complaint rests on questions and answers, which is exactly what a remote format is good at. The doctor will help you name what you actually feel and separate pre-faint light-headedness from spinning and from unsteadiness; go through the circumstances of the episodes; review your medicines for the ones that cause dizziness in their own right and tell you who to raise that with; explain which blood tests are worth doing and whether a rhythm recording is needed; and show you how to measure blood pressure lying and standing, along with what to change at home so you do not fall.

The limits of the format are obvious: nobody can measure your blood pressure through a screen, recording your heart tracing, and performing the tests that need a doctor's hands. And most important of all — dizziness with double vision, arm weakness, slurred speech, a severe headache, chest pain or loss of consciousness needs an ambulance, not a chat.

This material is for information only and does not replace medical advice.