Always feeling tired? It could be an underlying condition

Tiredness after a hard day's work is normal; constant tiredness is a warning. If lifestyle modifications aren't doing the trick, don't wait too long to get medical help

Man on desk — always feeling tired

Feeling tired is so much a part of modern life that many people regard it as routine and expected. But, while a strenuous job or unhealthy lifestyle can leave anyone exhausted at times, always feeling tired isn’t normal and can be a cause for worry.

Constant fatigue reduces the capacity to work and quality of life. Dr Galland-Decker et al. report in the British Medical Journal that a fifth of the population suffers from fatigue, with several different causes.

Feeling spent all the time can be the early sign of a grave health problem. However, the good news is that early diagnosis and treatment can reverse some of these disorders and prevent others from progressing. Unfortunately, many people do not seek medical help for fear of being labelled as lazy or fussy.

Are you always feeling tired?

Do you feel tired on most days, even after a good night’s rest, and never think that you’re functioning at your best? Don’t shrug it off. Review your lifestyle and see if you can tweak it to get more rest and better nutrition. Some fixes are easy, some not, but they’re worth trying before visiting your doctor. Lifestyle factors often underlying perpetual fatigue:

  • An improper or restrictive diet
  • Caffeine overload
  • Inadequate sleep.

If you’ve tried all the lifestyle fixes and you’re still tired all the time, respect the warning your body’s giving you. Diseases first showing up as fatigue can progress to a dangerous stage if ignored. Here’s list of top reasons that could be behind your feeling always tired.

Top reasons why you feel might be feeling constantly tired

1. Thyroid Deficiency

Thyroid deficiency, more common in women, usually results from an autoimmunity disorder. Reduced production of the thyroid hormones manifests as tiredness and excessive sleepiness.

Other signs are constipation, slow heartbeat, unexpected weight gain, and hoarseness. Women often have heavy periods.

Your doctor will diagnose thyroid deficiency [hypothyroidism] by measuring the thyroid hormone levels in the blood, by a blood test. It is simple to treat, requiring a dose of thyroid hormone every morning.

2. Diabetes

It’s not usual, but sometimes the first sign of diabetes is constant tiredness. Lack of energy, increased hunger and thirst, and an increased frequency of urination are the common signs of this disease.

Diabetes, if not controlled early, damages the heart, kidneys, nervous system, and other organs. Diagnosis is by urine and blood tests for glucose. Treatment doesn’t always mean drugs or injections; dietary and lifestyle changes can control diabetes for many years.

3. Anaemia

Haemoglobin in the red blood cells carries oxygen from the lungs to the rest of the body. A reduced amount of this vital molecule is called anaemia.

Anaemia can be because of:

  • Low production [deficiency of iron, folic acid, vitamin B12; blood cancers; genetic defects, and several other reasons].
  • Increased blood loss or destruction of the red blood cells [heavy periods, accidents and injuries with blood loss, hemolytic diseases].

Your doctor can often diagnose anaemia at a glance, but finding the cause needs laboratory investigations and diligence. The common causes of anaemia are nutritional and are straightforward to treat.

4. Mineral and Vitamin Deficiencies

Minerals like iron, magnesium, potassium, and others are vital for our body’s smooth running. They’re part of several enzyme systems, electrolyte balances, and metabolic pathways essential to our life processes. Vitamins also act on or facilitate several of the processes in our body.

Deficiencies of these crucial micronutrients cause tiredness and lethargy. They can be diagnosed by distinct clinical features apart from fatigue and confirmed by laboratory tests.

Most deficiencies are treated by altering the diet and providing oral supplements for a while. Some deficiencies [like vitamin B12] need a course of injections.

5. Heart Disease

A heart attack is dramatic and unmissable, but heart disease can be slow and sneaky, too. The heart gradually loses its capacity to pump blood efficiently, and fatigue is one of the early manifestations.

If you could easily climb up three flights to work but are now struggling and breathless, schedule an appointment with your doctor. Heart disease is one of the most frequent causes of sudden death.

6. Sleep Apnea

It’s pretty common, but not well known. Breathing slows or stops for a while during sleep, and blood oxygen levels drop.

Sleep apnea reduces the quality of sleep. Though you sleep enough, you don’t feel rested in the morning. Noisy breathing and snoring during sleep is a sign of partially blocked airways. Once your doctor suspects sleep apnea, a sleep study will establish the diagnosis.

Treatment is by a device used at night while you sleep. Called a CPAP [continuous positive airway pressure] machine, it keeps your airways open during sleep.

Obesity and smoking both contribute to this condition; you can help yourself by eliminating them. Sometimes, surgery is needed to clear airway obstruction.

7. Stress and depression

Mental health issues like stress, depression, and anxiety, etc. can leave you emotionally and physically tired. Apart from the direct effect, they also reduce the duration and quality of sleep, further contributing to tiredness.

Do you have difficulty sleeping at night and waking up in the morning? Do small tasks scare you? Are you finding it hard to concentrate on your work? These are common among people with depression. A mental health professional can help you.

8. Shift work sleep disorder

Do you work the night shift at your workplace? Or do your work hours change every week?

Working during the night, or at different times from time to time, is associated with poor sleep, appetite, and energy. Research has shown that those who work in clockwise shifts do better than those who function in anti-clockwise shifts. (Read more about the effects of shift work » Shift-proof your slumber)

9. Chronic Fatigue Syndrome [CFS]

CFS is also called myalgic encephalomyelitis. This is a condition lasting months, and we don’t yet know the cause.

The important manifestation is feeling sick after any physical effort. Other symptoms are tiredness, headache, sore throat, and joint pains. Fatigue persists even after sleeping well.

Chronic fatigue syndrome is a physical, bodily disorder, not a psychiatric or psychological one. Initially, it needs evaluation by a specialist in internal medicine.

Treatment is unsatisfactory and depends on the manifestations each individual has.

10. Restless Legs Syndrome

This is a condition of strange feelings in the legs when resting, relieved by movement. Sometimes, it manifests as aches and deep pain. Sufferers have to keep moving their legs or getting up to walk.

People suffering from this condition often have difficulty sleeping for years. Fatigue during the day is a frequent accompaniment.

11. Food Intolerance

Many people have low-grade allergies to food, called food intolerance. These don’t trigger dramatic reactions such as breathing difficulties, circulatory failure, etc., but cause long-term symptoms. Food intolerance often shows up as bloating, tiredness, anaemia, and digestive disturbances.

Once you realise food is causing your problem, you’ll have to work to identify the foods that cause your symptoms. Food and symptom diaries, elimination diets, and laboratory tests help in this. Changing your food habits to avoid the offending foods will usually see you regain your energy and enthusiasm.

12. Overweight or Obesity

Putting on weight puts a strain on your heart, skeleton, and muscles. The body has to work harder for usual things like walking to work and household tasks.

Constant fatigue and low energy levels often accompany obesity.

Other reasons for always feeling tired

Almost any disease that persists for a long time will drain you. While the illnesses listed below cause fatigue, it is rare for that to be the first manifestation.

  • Cancer
  • Mononucleosis
  • AIDS
  • Allergic rhinitis

Plan of action

Try the lifestyle fixes first.

Get enough sleep. Balance and regularise your meals. Drink plenty of liquids; dehydration often leads to feelings of tiredness.

Get some exercise. This sounds counterintuitive since you are already feeling so tired. But exercise improves your mood and confidence, and enhances the working of your heart, lungs, and muscles.

Losing weight, if you are overweight, is a good idea. It’ll not only give you a sense of purpose and achievement, but will also reduce the strain on your heart, bones, and joints.

If you’re still not feeling rested and energetic, make a medical appointment. As Drs Eccles and Davies point out, the “red flags” pointing to dangerous diseases will be looked for first. Further process will look for the cause of your fatigue and attempt to correct it.


The normal you should be healthy, enthusiastic, and whole. Your ability to live and enjoy your best life must be unrestricted.

Tiredness after a hard day’s work is normal; always feeling tired is a warning. If lifestyle modifications aren’t doing the trick, don’t wait too long to get medical help.

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