Lightheadedness

Lightheadedness is a common sensation that many people find unpleasant. It often feels like dizziness or a sense that one might faint. Some people describe the feeling as if their head is weightless. Others experience vertigo, which is the sensation that the room is spinning or moving.

This feeling is closely related to pre-syncope. Pre-syncope is the immediate stage occurring just before syncope, or fainting. During pre-syncope, a person might notice temporary visual field loss. This can feel like vision is getting dark or closing in.

To maintain balance, the brain must process several different types of information. It receives signals from the eyes and the inner ears. The nervous system also sends vital data to the brain. The brain must coordinate these various signals to keep the body steady. Lightheadedness occurs if the brain cannot process these messages correctly. This might happen if the signals are contradictory. It can also happen if the sensory systems are not functioning properly.

Many common factors can trigger a feeling of lightheadedness. A very frequent cause is a temporary shortage of blood or oxygen to the brain. This often results from a drop in blood pressure. Dehydration can also be a cause. Rapid dehydration can occur due to fever, vomiting, or diarrhea. Other common causes include low blood sugar and altitude sickness. Hyperventilation and panic attacks can also trigger the sensation. Some people experience postural orthostatic tachycardia syndrome. This is a condition where the heart rate increases when sitting up or standing.

In some cases, lightheadedness can indicate more serious medical conditions. Heart problems may cause an abnormal heart rhythm or a heart attack. Respiratory issues, such as pulmonary hypertension or a pulmonary embolism, are also possible. A stroke, bleeding, or shock can lead to these sensations as well. When these serious disorders are present, other symptoms usually appear. A person might feel chest pain or a racing heart. They might also experience a loss of speech or changes in vision.

Various external substances can also influence how a person feels. Certain medications may provoke dizziness. These include antihistamine drugs like levocetirizine, some antibiotics, or SSRIs. For people who do not use them often, nicotine or tobacco products can cause lightheadedness. Narcotic drugs, such as codeine, are also known to cause this sensation. Even common illnesses like the flu, the common cold, or allergies can accompany lightheadedness.

Treatment for lightheadedness depends entirely on the underlying cause. If dehydration is the problem, drinking plenty of water or fluids is helpful. However, if the cause is water intoxication, drinking more water is quite dangerous. If a person cannot keep fluids down due to nausea, they may need intravenous fluids. These are fluids delivered through a tube. Ringer's lactate solution is one type of intravenous fluid used. Eating something sugary can help if the cause is low blood sugar.

There are several simple ways to manage the sensation while recovering. A person should try lying down or sitting down. They can also reduce the elevation of the head relative to the body. For example, they might position their head between their knees. It is helpful to avoid bright lights and sudden changes in posture. When people are in extreme heat for a long time, they may sweat excessively. This sweating can cause a loss of essential electrolytes. Replacing these electrolytes can help prevent lightheadedness caused by heat.