Jakarta, ThedailyID — Feeling lightheaded, dizzy or like you might fall after standing up is a common experience. The sensation usually lasts only a few seconds before the body returns to normal.
One possible explanation is orthostatic hypotension, a drop in blood pressure that occurs when a person changes position.
When you stand, gravity causes around 500 to 1,000 milliliters of blood to temporarily collect in your legs and abdomen. This reduces the amount of blood returning to the heart.
The body normally responds by increasing the heart rate and narrowing blood vessels. If that response is too slow or weak, blood flow to the brain can temporarily decrease.
This can cause lightheadedness, blurred or darkened vision, weakness and even fainting. Some people may also experience a racing heart, shortness of breath or chest pain.
Several conditions can make the problem more likely:
- Standing up too quickly. The body may not have enough time to adjust to a sudden change in position.
- Dehydration. Losing fluids through sweating, vomiting or diarrhea can reduce blood volume and make it harder to maintain blood pressure.
- Anemia. A low red blood cell count can affect oxygen delivery and contribute to symptoms when standing.
- Certain medications. Some blood pressure drugs, diuretics and blood vessel relaxants can affect blood pressure or the body’s response to position changes.
- Diabetes. Long-term high blood sugar can damage nerves that help regulate blood pressure and heart rate.
- Heart problems. Abnormal heart rhythms or conditions that affect the heart’s pumping ability can contribute to the symptoms.
- Nervous system disorders. Problems affecting the autonomic nervous system can interfere with the body’s ability to regulate blood pressure.
Occasional lightheadedness after standing quickly may not signal a serious problem. However, frequent or worsening episodes, falls, fainting or symptoms that disrupt daily activities warrant medical evaluation.
Doctors can check blood pressure and heart rate while a patient is lying down and standing. They can then investigate possible causes such as dehydration, anemia, medication effects, diabetes, heart problems or nervous system disorders.
