If a person experiences a drop in blood pressure, fever, diarrhea, loss of hydration from vomiting or dizziness, lightheadedness can occur. Further, if the brain does not receive enough blood, it can cause lightheadedness as well. As people get older, they become more prone to lightheadedness, specifically if they rise up too quickly from sitting or lying down. Lightheadedness is often associated with the common cold, the flu and allergies. Many ear infections or conditions that cause ringing in the ears may also bring on lightheadedness. Medical conditions ranging from common to severe, which involve reduction in blood pressure and loss of oxygen or blood to the brain, usually produce lightheadedness.
Hypoglycemia is a condition characterized by having low blood sugar and the worsening of symptoms occurring hours after a meal is eaten. Along with fatigue, shortness of breath, feeling faint and many other symptoms, feeling hazy and lightheaded adds to the discomfort of this condition. According to DrPodell.org, scientific studies indicate that normalizing blood sugar is not the only concern relative to the cause of hypoglycemia, but that adrenalin, adrenal stress hormones and cortisol play a significant role. Consequently, it has been found that hypoglycemia symptoms are caused by overactivity of adrenalin and cortisol secretions, which normally function to keep blood sugar at adequate levels.
Heart attack is one of the more serious conditions that cause lightheadedness. During a heart attack, oxygen is prevented from getting to the heart and the rest of the body when blood vessels are blocked, causing the head to feel light and weightless. According to MedlinePlus, this has the tendency to happen while someone is exercising. A blood clot blocking the coronary arteries may also cause a heart attack. Heart attack creates a disturbance in the respiratory system sparking chest pain, heart palpitations, sweating, impaired vision and loss of speech. Stroke and abnormal heart rhythm can also produce lightheadedness.
When the nerves and the structures of the balance mechanism called the vestibular system develop problems in the inner ear, vertigo occurs. The balance mechanism senses when the head moves and when it changes position. Moving around and sitting up can make vertigo feel even worse. Vertigo can be serious enough to cause imbalance, upset stomach and vomiting. Lightheadedness in vertigo is normally characterized as feeling faint, dizzy and disoriented. According to MayoClinic.com, benign paroxysmal positional vertigo, or BPPV, causes short, strong flurries of vertigo right after changing the position of the head, such as while turning over or rising from sleep in the morning.