Causes of hypotension

A permanently low blood pressure may be inherited. The so-called essential hypotension (also: primary hypotension) is the most frequent form and usually affects young and slim women. There is no clear understanding as to why the pressure remains so low. Anyway, the tendency may be hereditary so that mother as well as daughter is affected frequently. If no complaints occur, essential hypotension is harmless. In fact, it may provide protection against diseases which are encouraged by high blood pressure. The risk of developing a sclerosis of the blood vessels (arteriosclerosis) and their consequences, such as coronary heart disease, heart attack, stroke or peripheral occlusive diseases, is lower in this case.

Secondary hypotension refers to a low blood pressure which is the consequence of a disease or an action of a drug.

Diseases which may cause hypotension are:

  • Thyroid hypofunction (hypothyreosis)
  • Hypofunction of the adrenal cortex (Addison’s disease)
  • Hypofunction of the pituitary gland (insufficiency of the anterior lobe of the hypophysis)
  • Heart diseases (such as cardiac insufficiency, rhythm disturbances, pericarditis, for example)
  • Long confinement to bed
  • Fluid volume deficit (hypovolaemia)
  • Lack of salt (hyponatriaemia)

 

Drugs which may cause hypotension are:

  • Psychopharmaceutical drugs (against depressions, anxiety, insomnia)
  • Antiarrhythmic drugs (against cardiac arrhythmias)
  • Antihypertonic drugs (against high blood pressure)
  • Diuretics (diuretic drugs)
  • Coronary drugs (in case of cardiac angina, such as nitro sprays)
  • Vasodilating drugs (vasodilatory agents)

 

Psychopharmaceutical drugs (against depressions, anxiety, insomnia)

In case of orthostatic hypotension (orthostasis = standing upright), the blood rushes into the lower parts of the body when sitting down or standing up fast. For a short period, the brain is supplied with less blood. Dizzy spells may occur, in the worst case causing the person to faint. This type of low blood pressure occurs frequently together with secondary hypotension. In most cases, however, the cause of the circulation problems can be disclosed by means of a Schellong test.

Potential causes for orthostatic hypotension are:

  • Secondary hypotension
  • Disorder of the autonomic nervous system (caused by diabetes, for example)
  • Nerve cell damage in the brain (caused by certain forms of Parkinson’s disease and hydrocephalus, alcohol abuse, for example)
  • Post-thrombotic syndrome (after deep leg vein thrombosis)
  • Varicose veins (varicosis)

What is hypotension?