Simon I'm so worried I looked up this stuff for you...
Common Causes Return to top
Lightheadedness happens when there is not enough blood getting to the brain. This can happen if there is a sudden drop in your blood pressure or you are dehydrated from vomiting, diarrhea, fever, or other causes. Many people, especially as they get older, experience lightheadedness if they get up too quickly from a lying or seated position. Lightheadedness often accompanies the flu, common cold, or allergies.
More serious conditions that can lead to lightheadedness include heart problems (such as abnormal heart rhythm or heart attack), stroke, and severe drop in blood pressure (shock). If any of these serious disorders is present, you will usually have additional symptoms like chest pain, a feeling of a racing heart, loss of speech, change in vision, or other symptoms.
The most common causes of vertigo are benign positional vertigo and labyrinthitis. Benign positional vertigo is vertigo that happens when you change the position of your head. Labyrinthitis usually follows a cold or flu and is caused by a viral infection of the inner ear. Meniere's disease is another common inner ear problem. It causes vertigo, loss of balance, and ringing in the ears.
Much less commonly, vertigo or feeling unsteady is a sign of stroke, multiple sclerosis, seizures, a brain tumor, or a bleed in your brain. In such conditions, other symptoms usually accompany the vertigo or imbalance.