Dizziness is a sensation when someone feels lightheaded and unbalanced or sometimes feels the whole world is spinning. Feeling of lightheadedness implies that the brain is not getting enough blood and oxygen. This symptom is very common and can occur in various conditions like: sudden drop in BP, dehydration (due to diarrhea, excessive sweating, vomiting, etc.) or an abrupt fall in blood sugar levels in diabetic patients. In serious ailments, dizziness is also quite prevalent. Some of these are: heart disease, internal bleeding or even heart attack. Ear infection and spondilytis may cause dizziness too. Certain drugs like antihypertensive and antibiotics can also instigate this problem.