lightheadedness

Lightheadedness is a term for a sensation of wooziness, faintness, or near-fainting, often due to transient reduction in blood flow to the brain. It is not the same as vertigo, which is a spinning sensation. Lightheaded episodes are usually brief and may recur.

Common causes include dehydration or heat, standing up quickly (orthostatic hypotension), low blood sugar, anemia, infections, and side effects from medications such as diuretics, blood pressure medicines, sedatives, or alcohol. Less commonly, heart rhythm problems or other cardiovascular conditions can contribute.

Evaluation by a clinician typically starts with a medical history and physical exam, followed by vital signs and orthostatic blood pressure measurements. Tests may include blood glucose, an electrocardiogram (EKG), and, if needed, blood counts, metabolic studies, or imaging to rule out serious causes.

Management depends on the cause. In an episode, lying down or sitting with the head level and legs raised can help. Hydration, avoiding rapid posture changes, and limiting triggers such as alcohol or overheating may prevent recurrences. Medical changes should be discussed with a clinician, especially if symptoms worsen.

Prevention focuses on addressing underlying conditions and lifestyle factors: stay hydrated, eat regular meals, avoid excess heat, stand up slowly, and manage chronic illnesses under medical supervision. Seek immediate care for fainting, chest pain, severe headache, trouble speaking, weakness, or confusion.