High blood pressure
Blood pressure is the force with which blood presses against the walls of the arteries. It is considered raised when readings taken at the clinic are 140/90 mmHg or higher on several occasions; for readings at home the threshold is slightly lower, 135/85 mmHg. A single high reading does not make a diagnosis. Blood pressure varies over the day, with exertion, with pain and with the clinic visit itself.
Raised blood pressure is common and becomes more common with age. In the great majority of people no single cause can be found. That does not mean it need not be taken seriously: blood pressure that stays too high for a long time puts a strain on the heart, kidneys, blood vessels of the brain and eyes, even when you feel perfectly well.
Why high blood pressure goes unnoticed for so long
Most people with raised blood pressure have no symptoms at all. That is exactly why it is often discovered by chance, during an examination for something else, at a blood test, or with a monitor that someone in the family bought for someone else.
When signs do appear, they are non-specific: a headache at the back of the head, especially in the morning, a feeling of pressure in the head, tiring easily, a flushed face, nosebleeds, ringing in the ears. None of them can be reliably put down to blood pressure until you measure it.
The reverse is also true. Feeling well is no proof that your blood pressure is under control, nor proof that the medicine you are taking is working. Measuring is the only way to know where you stand.
What raises blood pressure
Contributing factors include heredity, age, excess body weight, salt in the diet, alcohol, too little exercise, smoking, long-term stress and poor sleep, including breathing disorders during sleep. The combination matters more than any single factor.
A smaller share of raised blood pressure is the result of another illness. Diseases of the kidneys and renal arteries, hormonal disorders, thyroid disease and certain medicines can raise blood pressure. The latter include anti-inflammatory painkillers, decongestant nasal sprays, hormonal contraception, corticosteroids and stimulant preparations.
Looking for such a cause makes sense when high blood pressure appears suddenly, when the person is young, and when readings do not settle despite three or more medicines.
When not to wait for an appointment
If very high readings are accompanied by a severe headache with vomiting, disturbed vision, confusion, weakness or numbness on one side of the body, difficulty speaking, chest pain or severe shortness of breath, call 112 immediately. This is a hypertensive crisis and needs emergency care, not a booked appointment.
Do not drive yourself and do not wait for the reading to come down on its own. In such a situation, also do not try to lower your blood pressure quickly by taking an extra dose of medicine on your own, as a drop that is too fast can be just as harmful.
A high reading without the signs listed above is not an emergency. Sit down, rest for five minutes and measure again; if it is still high, book an examination and bring your record of readings with you.
How raised blood pressure is assessed
The examination at the cardiology clinic begins with a conversation about your readings, previous illnesses, medicines and risk factors. If you measure your blood pressure at home, bring a record of the last few weeks. The average of home readings is more useful for the assessment than one value measured at the clinic.
This is followed by a blood pressure measurement, a clinical examination and an ECG. Depending on the cardiologist's judgement, further options include an ultrasound of the heart to assess whether the heart muscle has already thickened because of the pressure, laboratory tests of kidney function, blood sugar and fats, and continuous blood pressure monitoring over a day and night when home and clinic readings do not agree.
The purpose of the examination is not just a number. Your overall cardiovascular risk is assessed, that is, what your blood pressure together with other factors means for you in particular and how quickly action is needed.
What treatment involves
The first part of treatment is not a medicine. Less salt, regular exercise, weight loss for those who are overweight, less alcohol and stopping smoking genuinely lower blood pressure. For mildly raised readings, this is sometimes enough.
When these measures are not enough or the risk is higher, medicines are introduced. Two or three active substances in smaller doses are often needed, because most people tolerate such a combination better than a single medicine in a large dose. The response is checked at a follow-up appointment and the doses are adjusted.
Treatment is long-term. With regular use your blood pressure comes under control, but if you stop, it returns within days or weeks. A controlled reading is the result of the medicine, not a sign that you no longer need it.