What causes high blood pressure?

Most of the time when people have high blood pressure, the cause is unknown. This is called primary hypertension. However, a few people may have something called secondary hypertension. This means that there is an underlying and possibly reversible cause of the high blood pressure. Some possible causes of secondary hypertension are:

• Certain medicines

• Kidney disease

• Obstructive sleep apnea

• Thyroid disorders

How will my doctor know to test for secondary hypertension?

Here are some signs and symptoms that may suggest your high blood pressure is caused by secondary hypertension:

• Central obesity (excess fat around the stomach)

• Cold or heat sensitivity

• Daytime sleepiness

• Flushing (skin turning red and hot)

• Gasping during sleep

• Headaches

• Heart murmur

• Large pad of fat on the back between the shoulders

• Loss of consciousness

• Low potassium levels in your blood

• Poor kidney function

• Slow or fast heart rate

• Snoring

• Stretch marks

• Sweating

You should also be tested for secondary hypertension if you are younger than 30 years, have a sudden rise in blood pressure after it has been controlled for a long time, or need more than three medicines to keep your blood pressure under control.