Low blood pressure, also known as hypotension, is when the blood pressure in your arteries is abnormally low. Blood pressure is recorded as two measurements in millimetres of mercury (mmHg):
- systolic pressure – the pressure when the heart beats and squeezes blood into your arteries
- diastolic pressure – the pressure when the heart rests between beats
People with a blood pressure of 90/60 are considered as having low blood pressure.
The symptoms of low blood pressure can be:
- blurred vision
- general feeling of weakness
- rapid breathing
When blood pressure drops suddenly, it may be a sign of a certain problem.
There are several causes for low blood pressure. They are:
- dehydration (when the body loses more water than it takes in, when you don’t drink enough liquids, if you sweat a lot during physical activity, fever, vomiting, severe diarrhea
- pregnancy, which goes away after delivery
- sudden drop after a meal in older people
- standing for a long time, called neurally mediated hypotension due to miscommunication between the brain and the heart
Certain medical conditions can also cause hypotension, such as:
- Heart conditions: heart attack, heart valve disease, bradycardia (a very low heart rate), and heart failure, which prevent the heart from pumping enough blood to the body
- Severe infections, like sepsis
- Endocrine conditions, such as thyroid disorders, Addison's disease, low blood sugar, and diabetes
- Central nervous system disorders, such as Parkinson's disease.
- Pulmonary embolism
Medications can also cause hypotension. These medicines include:
- Calcium channel blockers
- Angiotensin-converting enzyme (ACE) inhibitors
- Angiotensin II receptor blockers
- Beta blockers
Medicines for conditions such as anxiety, depression, erectile dysfunction, and central nervous system disorders also can increase your risk of hypotension.
Other substances, like alcohol, barbiturates, and some prescription and over-the-counter medicines can be the cause of hypotension.
A cause of severe hypotension is linked to shock. In shock, blood pressure drops very low and doesn't return to normal on its own. There are different types and causes of shock: septic (when bacteria enters the bloodstream), hypovolemic (when there is severe bleeding, loss of body fluids, swelling of the pancreas, severe diarrhea, severe kidney disease), cardiogenic (decreased ability of the heart to pump blood), vasodilatory (extreme relaxation of arteries due to a severe head injury, reaction to certain medicines, liver failure, poisoning) anaphylactic shock (allergy).
Low blood pressure can affect anyone. Some of the risk factors are: taking certain mediations, having another medical condition, such as diabetes, and a
The complications of hypotension are: dizziness, weakness, fainting, or getting insufficient oxygen for normal functions of the organs, which may even cause damages to the heart and brain,