The term fatigue describes an overall lack of energy and feeling of tiredness. It isn’t the same as feeling sleepy. There are many causes of constant fatigue. It can be due to lifestyle factors, physical health conditions or mental health issues. Identifying the cause of the constant fatigue can help with overcoming it, but it can be difficult to pinpoint the cause. 

Common symptoms of fatigue

Constant fatigue can cause you to suffer from the following symptoms:

  • Headaches
  • Apathy and a lack of motivation
  • Moodiness
  • Aching muscles
  • Slowed response times
  • Blurry vision
  • Daytime drowsiness
  • An inability to concentrate

Many of these symptoms are perfectly normal and can be typical of the busy lives that we lead. But if you start to accumate a collection fo these symptoms and/or they persist for a long time, then you might want to seei fyou can find a cause for your fatigue and seek to eliminate it.

Lifestyle factors that cause fatigue

Your lifestyle choices are often the root cause of your fatigue. It may be the result of:

  • Not eating a nutritious diet
  • Using too much alcohol on a regular basis
  • Smoking
  • Consuming too much caffeine
  • Not getting enough exercise
  • Lack of sleep
  • Being overweight
  • Menopause
  • Suffering from prolonged stress
  • Using illegal drugs
  • Taking certain medications

Changing your lifestyle can be difficult, but simply eating a healthy diet and getting enough sleep helps to reduce fatigue for many people. If you can lose weight, give up alcohol, stop smoking, and manage your stress, you may just find you don’t suffer from constant fatigue anymore. 

One treatment for fatigue caused by lifestyle choices, that seems to be gaining popularity and celebrity endorsement recently, is using an IV drip containing a vitamin infusion or similar. If you want to know how to get IV fluids at home in the UK, Drip Hydration, boost IV and NAD Clinic offer mobile IV therapy that can help you to overcome your fatigue and boost your energy levels. Treatments take about 45 to 60 minutes and are administered by certified nurses. This treatment is still not widely accepted by the medical profession and I would advise that you do your own research very carefully, consult a doctor first and ask their opinion about whether this treatment would be suitable for your condition before proceeding.

Physical health conditions that cause fatigue

Fatigue that doesn’t seem to respond to healthy lifestyle changes, may be associated with a physical health problem. Anaemia, for example, is due to a lack of healthy red blood cells to carry oxygen to your body’s tissues. This iron deficiency can make you feel extremely tired and weak. Taking iron supplements or receiving an iron infusion can help. 

Sleeping disorders like insomnia and sleep apnoea can prevent you from getting to sleep or cause you to wake up during the night. This can make you feel exhausted during the day. Eating disorders like anorexia also commonly cause fatigue because your body doesn’t get the nutrients it needs to give you energy. 

Autoimmune disorders, kidney disease, cancer, congestive heart failure, underactive thyroid, and emphysema are other physical health problems that can make you feel constant fatigue, and more recently , there are people with long COVID who are reporting severe fatigue symptoms too. Treatment of fatigue caused by physical health conditions will depend on the diagnosis.

Mental health issues that cause fatigue

Fatigue is a common symptom of mental health issues such as depression or anxiety. Mental fatigue can make it difficult to concentrate or focus. Depression can drain you of all your energy, and you may either sleep too little or too much. 

When you feel anxious, your body goes into ‘fight or flight’ mode, and you use up all its energy stores. Constant stress means your body produces cortisol all the time, which can affect your immune system and make you susceptible to infections. Infections from viruses like influenza can also make you feel fatigued. 

Grief is another mental health condition that can cause fatigue.

When to see a doctor

If changing your lifestyle and your sleep habits doesn’t help you overcome your fatigue, you need to speak to a doctor. You could have a physical condition that’s causing your fatigue. 

Doctors will usually do some blood tests depending on what they think is causing the fatigue. A blood test may reveal a condition like anaemia where taking an iron supplement could help. It could pick up an underactive thyroid where medication is necessary, or possibly a food intolerance which is stopping you from getting as much energy as you need from your food. Urine tests, imaging scans, and mental health questionnaires may also be necessary, depending on your other symptoms.


A range of lifestyle factors, physical health problems, and mental health issues could cause fatigue. It can be quite difficult to determine the cause of fatigue because there are so many different causes. It helps to address lifestyle factors first to see if your fatigue improves. All you may need is a better diet and more exercise. If changing your lifestyle and improving your mental health does not help, your fatigue may be due to a physical health problem that needs to be diagnosed by a doctor.

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