Hypertension - What causes it?

Although there are risk factors involved, there is no identifiable cause of high blood pressure in 90 to 95% of the cases. This type of blood pressure is called primary hypertension. Secondary hypertension (5-10% of the cases) is caused by conditions such as kidney disease, adrenal disease, thyroid disease, abnormal blood cells, preeclampsia or sleep apnea.

Sometimes medications such as birth control pills, cold remedies, decongestants, prescription drugs and over the counter pain relievers can be a cause. In these cases, once the cause is removed, the blood pressure returns to normal.