Low blood pressure
Low blood pressure (hypotension) has many possible causes, from lifestyle choices, to medication or an underlying health condition.
In some cases, it may just be the result of being healthy and active or a tendency you've inherited from your parents.
Throughout the day, it's normal for your blood pressureto vary depending on what you're doing. Stress atwork, the temperature outside andyour dietcould allaffect your blood pressure reading.
This is whyit's important your blood pressure is checked under similar conditionseach timeto ensureresults are consistent.
If your blood pressure reading is low, your GP will first consider whether it has been affected by:
If your blood pressure is still considered low after taking these factors into account, there may be another cause. Some possibilities are explained below.
Some research has suggestedlow blood pressure is Genetics . If your parents have low blood pressure, it's possible you could inherit it from them.
Yourblood pressure usually increases as you get older, but a drop in blood pressure from movement or eatingismore commonwith age.
Some types of medication may causelow blood pressure, including the following:
Your GP will discusspossible side effects with you when prescribing medication, andyour blood pressure will be carefully monitored if you're considered to be at risk of hypotension.
Dehydration can occur if fluid is lost, either through skin from excessive sweating in hot weather, or from the gastrointestinal tract as a result of vomiting or diarrhoea .
Examples of conditions and illnesses that can lead to low blood pressure are given below. Prolonged bed rest can also lower blood pressure.
Low blood pressure can sometimes be caused by anaemia ,where the amount of haemoglobin in the blood is below the normal level or there are fewer red blood cells than normal.
A heart condition, such as heart disease or a heart attack , can cause low blood pressure becauseyour heart may not be able to pump blood around your body.
Neurological disorders, such as Parkinson's disease ,are conditions that affect your nerves. Low blood pressure can occur if part of your nervous system called the autonomic nervous system is affected.
Your autonomic nervous system controls bodily functions you don't actively think about, such as sweating and digestion. It also controls the widening and narrowing of your blood vessels.
If there's a problem withyour autonomic nervous system, your blood vessels could remain too wide,which can cause low blood pressure.
Having a condition that affects theproduction of certain hormones in your bodycan also cause low blood pressure. Examples are diabetes and Addison's disease .
In Addison's disease, the immune system attacks and damages the adrenal glands, two small glands above your kidneys that produce hormones to control your blood pressure and maintain the balance of salt and water in your body.
Low blood pressure can also occur if your adrenal glands become damagedfor example,because ofaninfection or tumour.
Low blood pressure that occurs after standing for long periods of time (neurally mediated hypotension) happenswhen your body tells the brainyour blood pressure is too high when it's actually too low. This causesyour brain to slow down the heartbeat, further reducing your blood pressure.
Low blood pressure canbe caused by serious injuries or burns, particularly if you lose a lot of blood. Low blood pressure can also occur if you go into shock after a serious injury.
Septic shock and toxic shock syndrome
Septic shock and toxic shock syndrome are caused by bacterial infections. Bacteria attack the walls of the small blood vessels, causing them to leak fluid from the blood into the surrounding tissues. This causes a significant drop in blood pressure.
Anaphylactic shock , or anaphylaxis, is caused by an allergic reaction. During an allergic reaction, your body produces a large amount of a chemical called histamine, which causes your blood vessels to widen, leadingto a sudden severe drop in blood pressure.
Cardiogenic shock occurs when your heart cannot supply enough blood to your body,leading to a drop inblood pressure. This can happen during a heart attack.
Low blood pressure, also known as hypotension, is where blood pressure in your arteries is abnormally low.
Symptoms of low blood pressure (hypotension) include dizziness, nausea and feeling weak. If your blood pressure is naturally low, it's unlikely to cause any symptoms or require treatment.
Low blood pressure (hypotension) has many possible causes. Some are everyday factors, while some people have an underlying cause that requires treatment.