This leaflet answers common questions about the complex hypertension clinic. If you would like further information, or have any worries, please do not hesitate to ask your nurse or doctor.

What is the complex hypertension clinic?

Complex hypertension is when high blood pressure occurs in patients below the age of 40 and/or cannot be fully controlled with the use of three blood pressure tablets. In this group, it is more common to find an underlying cause for hypertension.

Having high blood pressure is usually a life-long condition, mainly cared for by your GP who are experts at this. You have been referred to the complex hypertension clinic because your GP has noticed your blood pressure is difficult to control or was diagnosed at a young age (typically under 40 years).

The aims of the clinic are to: 

  • confirm if you have difficult to control blood pressure 
  • look for underlying causes for high blood pressure 
  • identify with you those lifestyle measures that will help you control your BP  
  • describe the treatments that we think are best for control of blood pressure.  

On average, people are seen on one to three occasions before being discharged back to the care of their GP. 

Before visiting the clinic

To make the most out of the clinic, you may be asked to take certain tests before we see you. This is to investigate an underlying cause for your high blood pressure.  

There are three types of tests you may need:

  • urine test
  • blood test
  • a scan.  

Urine tests

We will ask you to provide a urine sample at your clinic appointment. 

Blood tests

The consultant will request the blood tests for you. The doctor will review your current medication and may ask you to change your blood pressure medications two to six weeks before having your blood tests. 

Some of the blood tests check specific hormone levels that can cause high blood pressure. Hormone levels are affected by various blood pressure medications. To get accurate results, you cannot be taking most blood pressure tablets (this doesn’t apply if you are taking tildiem, doxazosin, and/or hydralazine).  

We will contact you to make sure you are on the correct medications and let you know when to have your blood tests. When you have been off any blood pressure tablets for the specified length of time, you will need to book your appointment for 9am blood tests at one of the Royal Free London hospitals.

Book your blood tests

Visit the blood tests page on our website for information on how to book your blood test at our hospitals and sites.

If you have stopped your usual medication for the blood test, you can go back on your original medication after the blood test if you wish or wait until your clinic appointment to discuss this. 

What scans will I have?

Some patients will need a scan looking at their kidneys and blood vessels. The most common scans are an ultrasound (the same type of scan ladies have during pregnancy) or an MRI scan with an injection of a special dye.   

MRI scans use magnets and radio waves to make images of the body. This safe procedure can take longer than X-rays or CT scans and might not be suitable for people with certain medical devices such as pacemakers. Our radiology team will check with you when they book the appointment. 

We will request for you to have these tests on our system before you attend the complex hypertension clinic, and you will receive an invitation by post or via the My RFL patient portal.

What will happen at my clinic appointment?

After you have had the tests, the doctors have ordered, you will receive an appointment to come to the complex hypertension clinic, in the kidney and urology centre on the third floor of the Royal Free Hospital. 

At this appointment, the team will:

  • review and explain your results 
  • review your blood pressure control 
  • talk about things that you can do to help control your own blood pressure, looking at lifestyle measures which are often very effective
  • review what the best medication combination is for you   
  • provide advice to your GP on the next steps for blood pressure control if your current regime is not working.

Do I need to bring anything with me?

Please bring a list of the tablets you are taking and their specific dose (consider taking a picture of the boxes if easier) to your clinic appointment. 

Checking your blood pressure at home is helpful when reviewing your blood pressure control. If you check your blood pressure at home, we would be grateful if you could bring in the results for us to review (this could be written on a piece of paper or recorded on any dedicated mobile phone app).  

To check your blood pressure at home, we recommend blood pressure machines which measure your blood pressure around the upper arm (for example, OMRON M2 or similar). Blood pressure should be checked after five minutes of seated rest and three readings should be taken on each occasion. We would recommend you ignore the first measure and record the second and third readings.  

It can also be helpful to write down any questions you would like to ask the doctor in the clinic appointment. 

After your clinic appointment

You will only need to be seen in the clinic once or twice. Where an underlying cause for your hypertension is found, you may need further investigation, and you will be referred on for further tests.

In most patients however, no underlying cause is found. If this is the case, we will give optimal guidance to your GP to treat and monitor your blood pressure effectively