High blood pressure (hypertension) - Causes 

Causes of high blood pressure 

In more than 90% of cases, the cause of high blood pressure (hypertension) is unknown but several factors can increase your risk of developing the condition.

Where there is no specific cause, high blood pressure is referred to by doctors as primary or essential hypertension.

Factors that can raise your risk of developing primary hypertension include:

  • age – the risk of developing high blood pressure increases as you get older
  • a family history of high blood pressure (the condition seems to run in families)
  • being of African or Caribbean origin
  • a high amount of salt in your food 
  • a lack of exercise
  • being overweight or obese
  • smoking 
  • drinking large amounts of alcohol

Known causes

About 10% of high blood pressure cases are the result of an underlying condition or cause. These cases are referred to as secondary hypertension.  

Common causes of secondary hypertension include:

Find out about how to get your blood pressure tested.

Page last reviewed: 04/07/2014

Next review due: 04/07/2016


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The 2 comments posted are personal views. Any information they give has not been checked and may not be accurate.

glenscot said on 22 June 2014

I have for years suffered with allergies and intolerances esp to food but also chemicals. In April this year the effect went further and it was thought I had an TIA though all tests are negative inc MRI scan. Last year nothing I can prove etc. What happens is that some 36 to 48 hours after the food eaten my BP goes up and so does the pulse and then I go to the loo, maybe four times or so over s few hours usually 4. Once I have got rid of the offending food I am back to normal. I cannot get my GP to agree this is so and it started in 1944 after a peanut butter sandwich. I am now 72. The reactions are getting worse. I qualified in ND HD HMD and also a PhD in Immunology. I do take Creon with every meal.
I would like to do some research on this and wondered if anyone could tell me of any books I can look at which has these symptoms in it. or point me to some research, With my symptoms I am convinced there must be others like me.
I have had many tests back in 1990's but not recently.

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LucyLuLu said on 05 April 2014

I am a really healthy person aged 50. I have a good BMI, do lots of yoga and exercise regularly.

In September 2013 I made a conscious decision to give up ordinary tea and coffee in favour of herbal teas as I am very health conscious and felt that this would be better for me. I eat only organic food, drink virtually no caffeine and drink only herbal teas (my favourite being liquorice and spearmint).

However, in December 2013 I had a routine health check and was diagnosed with high blood pressure (at times it went as high as 220/110) and no-one couldn't figure out why. All the blood tests and my ECG came back clear. I don't drink, smoke or have diabetes.

The Doctor's diagnosis was that I must have essential hypertension and I was prescribed two different ACE inhibitors, both of which I reacted to very badly (sickness, headaches, lethargy, hot sweats, lack of sleep). The Doctor then suggested that we give my body a rest to recover before prescribing further drugs.

It was at this point that I decided to look at homeopathic medicines and started to search the internet for possible remedies. Purely by chance I stumbled on a site that mentioned foods to avoid as well as foods to help and one of things mentioned that should be avoided is liquorice.

I didn't realise, but apparently consumption of liquorice can lead to dangerously high blood pressure and dangerously low potassium levels (hypokalemia). Liquorice contains glycyrrhizinic acid, which sets off a chain reaction of biochemical events in the body resulting in high blood pressure.

I was drinking around 4 to 6 cups of liquorice and spearmint tea every day and since giving it up my blood pressure has dropped dramatically and it is now very obvious that this was the cause. Apparently, it is also recommended that for those taking ACE inhibitors that liquorice should be avoided.

I thought I should share this in case there are others who are experiencing similar problems.

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