Low Blood Pressure (Hypotension): Symptoms, Causes and What to Do

Most of us worry about high blood pressure, but low blood pressure can be just as troublesome when it makes you dizzy, weak and close to fainting. Some people have naturally low readings and feel perfectly fine, while for others it is a sign of dehydration, illness or a medicine side effect. Here is how to tell the difference.

What counts as low blood pressure?

Blood pressure is measured as two numbers, for example 120/80 mmHg. Low blood pressure (hypotension) is generally a reading below 90/60 mmHg. What matters more than the number is whether you have symptoms. A person with 100/60 who feels fine does not need treatment, while one with 110/70 who faints after a sudden drop does.

Symptoms

• Dizziness or light-headedness, especially on standing up
• Blurred or darkening vision
• Weakness and tiredness
• Nausea
• Fainting or near-fainting
• Cold, clammy, pale skin
• Rapid, shallow breathing and confusion in serious cases such as shock
• Trouble concentrating

Common causes

• Dehydration: from heat, fasting, vomiting, food poisoning or diarrhoea, and not drinking enough water
• Standing up quickly (postural or orthostatic hypotension), particularly in older adults
• Medicines: blood pressure tablets (see high blood pressure), water tablets, some antidepressants, and prostate medicines such as alpha-blockers
• Anaemia, see iron deficiency anaemia, and vitamin B12 deficiency
• Low blood sugar, or poorly controlled diabetes
• Heart conditions: a slow heartbeat, valve problems, heart failure or heart attack
• Hormonal causes: thyroid disease, and adrenal gland problems
• Pregnancy, in the first and second trimesters, where BP naturally falls
• Severe infection (sepsis), bleeding or an allergic reaction. These are emergencies.
• Ramadan fasting, long standing, hot bath and hot weather

What you can do at home

• Drink more water. Aim for steady fluids through the day, and take ORS if you have had vomiting, diarrhoea or heavy sweating.
• Eat small, frequent meals. Large heavy meals can cause BP to drop after eating.
• Add a little more salt only if your doctor agrees. It is not suitable for people with heart, kidney or high BP problems.
• Stand up slowly, sit on the edge of the bed for a minute first, and avoid standing still for long.
• Wear compression stockings if advised, to stop blood pooling in the legs.
• Avoid hot showers, alcohol, and prolonged heat exposure.
• Raise the head of the bed slightly if morning dizziness is a problem.
• If you feel faint, sit or lie down with your legs raised.
• Tea and coffee can raise BP slightly for a short time, but do not rely on it.

Check your blood pressure properly

Measure it sitting calmly for five minutes, with the arm supported at heart level, and also after standing for one to three minutes if you feel dizzy. Keep a record. Our guide on how to check blood pressure at home explains the steps.

Treatment by a doctor

Treatment depends on the cause: stopping or changing a medicine that lowers BP, treating anaemia, thyroid or sugar problems, replacing fluids, or medicines that raise blood pressure in severe or persistent cases. Please do not stop your own blood pressure medicines without your doctor’s advice, as high blood pressure can return and cause harm.

Emergency: go to hospital if

• You faint, especially with chest pain, palpitations or breathlessness
• You have confusion, cold clammy skin, a rapid weak pulse and very low BP
• You have signs of shock after bleeding, severe infection, or allergic reaction
• You have low BP together with black stools or vomiting blood

Key takeaways

• A BP below 90/60 matters only if you have symptoms such as dizziness, weakness or fainting.
• Dehydration, standing up quickly, medicines and anaemia are common causes.
• Fluids, small meals and slow movements help. Salt should only be increased on medical advice.
• Fainting, chest pain or shock-like signs need emergency care.

Related products on Medimart

• Oral rehydration salts (ORS): replace fluids and salts
• Multivitamin: sometimes used when poor diet contributes to weakness, after advice

You can monitor your readings at home with a blood pressure monitor from Medimart, delivered across Pakistan.

This guide is for general information and does not replace advice from a doctor.