There are lots of reasons for chronic tiredness and quite a few of these will become obvious on examination of lifestyle. However, always feeling tired despite having adequate sleep can be a symptom of underlying illness which can often be detected by simple blood tests and may well be easily treatable.
The reasons for tiredness can be categorised according to the nature of the cause.
Lifestyle
- Lack of sleep: an obvious one this but the reason for the inadequate sleep might not be so clear. Worry is a common cause that may be obvious but sleep apnoea is less noticeable. There are very many reasons for poor sleep and these merit separate investigation.
- Weight: being over or under weight may lead to lack of energy and tiredness
- Poor diet: this is likely to bring about a deficiency in important vitamins and minerals. These are necessary for proper functioning of the body’s energy handling processes.
- Lack of physical exercise: our bodies were designed to move around quite a bit so that blood can circulate properly, muscles are fully utilised and the cells well oxygenated – lack of exercise will lead to tissue fatigue and tiredness.
Inflammation
- Infection: this stimulates the immune system which reacts by producing large numbers of white blood cells and antibodies. All this takes much energy which may be diverted from other areas and give rise to tiredness.
- Autoimmune disease: the inflammatory reaction is a major component of the immune response. In autoimmune disease there is no infection but the inflammatory process is triggered against the body’s own tissues. Chronic inflammation anywhere in the body is likely to lead to tiredness.
Glandular
The thyroid gland is intimately involved in controlling body metabolism. Low thyroid function slows down many cells in the body, they then take up oxygen and glucose more slowly and fatigue results.
Cardiovascular
- Poor heart output: this could be from blocked coronary arteries or faulty heart muscle. It will lead to inefficient circulation and therefore poorly oxygenated tissues and consequent tiredness.
- Anaemia: in this case the heart is ok but the blood itself has poor oxygen content because of a defect in haemoglobin or the red blood cells. There are various types of anaemia – iron deficiency being the most common.
Pregnancy
Both mother and growing baby are calling on mother’s energy reserves so it’s not surprising that tiredness is common in pregnancy. It’s possible that the hormone changes which take place during pregnancy may also give rise to tiredness.
Fibromyalgia
Extreme tiredness is a cardinal symptom of this disorder.
Psychological
Both depression and anxiety can give rise to tiredness. In some cases constant tiredness may be the only symptom of depression. Anxiety seems to bring on bouts of tiredness for reasons other than simply lack of sleep due to worry.
Drugs
A good many medicinal drugs have a sedative action so if you are constantly tired check your medication out with the doctor.
If you are tired all of the time, you should consult your doctor. If no cause can be found then take up regular exercise - in the fresh air if you can - and adopt a healthy diet. You may end up feeling much less tired and will probably live longer.
Resource
Medicine. eds. Souhami and Moxham. Pub. Churchill Livingstone 2002
