Dizziness and light-headedness

What dizziness actually means

The term dizziness can describe several different sensations, and the words people use matter more than they expect. Some people feel light-headed, as though they might faint. Others describe a spinning sensation, known as vertigo. There are also people who experience a general sense of imbalance.

When considering whether dizziness may be related to a heart problem, the type of dizziness matters. In practice, heart-related dizziness is more often described as light-headedness or a feeling of near fainting, rather than as a spinning sensation.

One of the most important points to remember is that dizziness is a symptom, not a diagnosis. Many of its causes are harmless, but identifying the underlying reason is what allows the right thing to be done about it.

• Light-headedness, or a feeling that you might faint, which is the pattern most often linked to the heart
• A spinning sensation, known as vertigo, which is usually related to the inner ear
• A general sense of imbalance or unsteadiness

The common causes that are not the heart

There are many situations where dizziness has a cause that has nothing to do with the heart, and these are the everyday explanations that account for most episodes. Vertigo, which creates a spinning sensation, is usually related to the inner ear rather than the heart.

One of the most frequent causes of feeling faint is vasovagal syncope, where the body overreacts to triggers such as pain, emotional stress or standing for long periods. That leads to a temporary drop in heart rate and blood pressure. Causes of this kind are generally benign, even though they can be distressing at the time.

These forms of dizziness often improve with rest, hydration, or by addressing whatever is behind them. If your symptoms persist, keep returning or are simply unclear, it is still worth having them investigated properly rather than left.

• Inner ear problems, which typically cause vertigo rather than light-headedness
• Dehydration
• Anxiety or stress
• Low blood sugar
• Sudden changes in position, such as standing up quickly
• Heat exposure
• Vasovagal syncope, the body overreacting to pain, emotion or prolonged standing

How the heart can cause dizziness

The brain depends on a steady supply of oxygen-rich blood. If that supply is reduced, even briefly, it can lead to dizziness or fainting. There are several ways the heart can contribute to this.

If the heart beats too slowly, it may not pump enough blood to meet the body's needs. This is often seen in heart block and in sick sinus syndrome, where people may experience fatigue, light-headedness or episodes of fainting. In tachy brady syndrome the rate swings the other way as well, between periods of a slow rate and sudden bursts of a fast one.

When the heart beats too quickly or irregularly, it may not fill and pump effectively, which can reduce blood flow to the brain. Atrial fibrillation, atrial flutter, supraventricular tachycardia, atrial tachycardia and ventricular tachycardia can all present in this way.

A sudden drop in blood pressure can also cause dizziness. Readings lower than 90/60mmHg are classed as hypotension, and low blood pressure may occur when standing up quickly or as a result of dehydration, medication or certain medical conditions. In some cases the heart does not respond quickly enough to maintain stable circulation.

Conditions affecting the heart muscle or valves can reduce the efficiency of blood flow as well. Here the dizziness tends to appear alongside breathlessness or reduced exercise tolerance, particularly in heart failure or cardiomyopathy, and particularly when demand rises during physical activity.

• A slow heart rhythm, so the heart does not pump enough blood to meet the body's needs
• A fast or irregular heart rhythm, so the heart cannot fill and pump effectively
• Low blood pressure, whether from posture, dehydration, medication or a medical condition
• A structural problem with the heart muscle or valves, which limits how the heart responds to demand

When dizziness is more likely to be heart related

Not all dizziness is caused by the heart, but certain patterns raise concern, and these are the ones Dr Jogiya pays closer attention to. A blackout that arrives with no warning symptoms at all is a particularly important one, because it can point towards a cardiac cause rather than a benign one.

Dizziness or fainting that happens during exertion is always taken seriously and should always be investigated promptly. The same applies if you already have a known heart condition and your symptoms change.

There is one pattern that belongs in a different category altogether. Nausea, sweating and light-headedness, alone or combined with other symptoms, can be signs of a cardiac event, particularly during a heart attack. If light-headedness or fainting arrives with sweating, sickness, breathlessness or pain spreading to the arm, jaw, neck or back, that is a 999 call rather than something to book an appointment about.

A common mistake is to dismiss these symptoms, particularly if they are brief. What tends to happen is that people wait until the episodes become more frequent before seeking advice. Early assessment is always preferable.

• It occurs during physical activity
• It is associated with palpitations
• It leads to fainting or near fainting
• It happens suddenly, without an obvious trigger or any warning
• It occurs alongside chest discomfort or breathlessness
• It happens more than once, or an episode results in injury
• It happens in someone already known to have heart disease

How Dr Jogiya investigates dizziness

When assessing whether dizziness is related to a heart problem, the goal is to understand what is happening to the circulation and to the heart rhythm. The evaluation usually begins with a detailed discussion of your symptoms, and Dr Jogiya will often ask when the dizziness occurs, how long it lasts, and whether it is linked to activity or to a change of posture.

Blood pressure is then measured directly, including lying and standing readings, and tests of the heart itself are used to look for a rhythm or structural cause. Which tests are arranged depends on your history and on what you have noticed.

Symptoms often come and go, which can make diagnosis more challenging. This is where longer monitoring, wearable monitors and digital health tools have become increasingly valuable, because capturing the heart rhythm during an episode is frequently what provides the answer. In some cases longer term monitoring or additional imaging may be required.

• A 12 lead ECG to assess the heart rhythm
• Blood pressure measurements, including lying and standing readings
• An ECG monitor worn over a longer period to detect intermittent rhythm problems
• An echocardiogram to assess the structure and function of the heart
• A tilt test, which assesses the causes of dizziness and loss of consciousness by reproducing your symptoms while your heart is monitored

What you can do, and when to get seen

If you feel light-headed or sense that you may faint, sit or lie down immediately. Beyond that moment, a few practical steps can help reduce symptoms, particularly where the dizziness is related to blood pressure, posture, hydration or lifestyle.

These simple measures can sometimes reduce how often episodes happen, but they should not replace medical assessment when symptoms are persistent, recurrent or unexplained. Outside an emergency, arrange an assessment promptly if dizziness or fainting happens more than once, happens during exercise, occurs without any warning, or comes alongside chest discomfort or palpitations. Persistent or unexplained dizziness should be investigated rather than left.

Early evaluation often provides reassurance when the cause turns out to be harmless, and where a heart condition is identified it allows appropriate treatment to begin before more serious complications develop. This page is general information about dizziness and light-headedness. It is not a substitute for individual medical advice, which needs a consultation and your own test results.

• Sit or lie down as soon as you feel light-headed
• Stay well hydrated
• Rise slowly from sitting or lying rather than standing up quickly
• Avoid standing still for prolonged periods
• Maintain regular meals
• Prioritise sleep and manage stress
• Keep a note of when symptoms occur and what you were doing at the time