Certain medications: A number of drugs can cause low blood pressure, including diuretics and other drugs that treat hypertension; heart medications such as beta blockers; drugs for Parkinson’s disease; tricyclic antidepressants; erectile dysfunction drugs, particularly in combination with nitroglycerine; narcotics and alcohol. Other prescription and over-the-counter drugs may cause low blood pressure when taken in combination with high blood pressure medications.
Orthostatic hypotension is caused by a sudden change in body position. This occurs most often when you shift from lying down to standing. This type of low blood pressure usually lasts only a few seconds or minutes. If this type of low blood pressure occurs after eating, it is called postprandial orthostatic hypotension. This type most often affects older adults, those with high blood pressure, and people with Parkinson disease.
4. Find an exercise that works for you (and do it). Moving more can help reverse high blood pressure. One meta-analysis of 65 studies found regular exercise provides both an acute and longer-term reduction in blood pressure. Whether you’re an exercise novice or a conditioned athlete, these four strategies can help you create an effective workout plan to optimize health.
A slow heart rate (bradycardia) can decrease the amount of blood pumped by the heart. The resting heart rate for a healthy adult is between 60 and 100 beats/minute. Bradycardia (resting heart rates slower than 60 beats/minute) does not always cause low blood pressure. In fact, some highly trained athletes can have resting heart rates in the 40s and 50s (beats per minute) without any symptoms. The slow heart rates are offset by more forceful contractions of the heart that pump more blood than in non-athletes. However, in many patients bradycardia can lead to low blood pressure, lightheadedness, dizziness, and even fainting.
If your blood pressure is above the normal range for up to 5 readings (taken at different visits), your doctor will likely diagnose you with high blood pressure. Sometimes the doctor may diagnose you after a fewer number of readings, depending on how high above normal your blood pressure is and if you have other medical conditions. Blood pressure tends to be at its highest during exercise, physical work, or stress, and lowest during sleep. Everyone can have a temporary increase in blood pressure at one time or another, which is why it's important to take multiple readings.
Allergic reaction (anaphylaxis): Anaphylactic shock is a sometimes-fatal allergic reaction that can occur in people who are highly sensitive to drugs such as penicillin, to certain foods such as peanuts or to bee or wasp stings. This type of shock is characterized by breathing problems, hives, itching, a swollen throat and a sudden, dramatic fall in blood pressure.