Low blood pressure, or known as hypotension, is a condition where the blood pressure is lower than the normal. The normal blood pressure is around 120/80 mmHg. If your blood pressure is lower than that, the blood flow to some of your vital organs, like your brain and lungs, can be restricted. This leads to symptoms such as dizziness, fainting and blurred vision.
There is no exact threshold for low blood pressure. If your blood pressure is lower than 90/60 mmHg, your doctor may consider it to be low. However a blood pressure lower than this may be completely normal for some people, whereas others may experience symptoms of low blood pressure at a much higher level. It also depends on individual factors: blood pressure is usually lowers in young women, especially in pregnant women. So, it is only considered to be a problem if you are having symptoms.
What Causes Low Blood Pressure?
Low blood pressure can be caused by many factors, including the following:
Dehydration is the most common cause of low blood pressure. When you become dehydrated, the body loses more fluid than it takes in which in turn decreases the blood volume in your body, resulting in a drop in blood pressure.
Diarrhea, vomiting, overuse of diuretics, and strenuous exercise can all lead to dehydration. If left untreated, it can lead to severe hypovolemic shock, a condition that can be life-threatening.
- Heart problems
Some heart problems that can lead to low blood pressure include irregular heartbeat (arrhythmia), heart attack and heart failure. These conditions may cause low blood pressure because they prevent the body from being able to pump adequate amount of blood.
Some types of medications that can cause low blood pressure, including:
- High blood pressure medications, such as diuretics, ACE inhibitors, alpha-blockers, and beta blockers
- Depression medications, such as amitriptyline (Elavil)
- Parkinson’s disease medications, such as levodopa-carbidopa (Sinemet)
- Erectile dysfunction drugs, such as sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis)
Blood pressure is likely to drop when you are pregnant, especially during the first 24 weeks of pregnancy.
- Blood loss
Blood loss due to injury or severe internal bleeding reduces the amount of blood in the body, thus lead to a drop in blood pressure.
Any inflammation in the body can also cause low blood pressure. This is because the blood supply will be concentrated around the inflammation area and causing blood supply to parts of the body becomes reduced.
Anemia is a condition in which your body does not produce enough red blood cells. In addition to making you feel tired, it can also lead to low blood pressure.