Skip to content

Get the latest service status updates

Why do I feel tired all the time?

Find out if you are simply doing too much or whether there could be an underlying reason for your symptoms.

Do you find yourself feeling exhausted even when you have had a good night sleep? It can be difficult to know whether you are simply doing too much or an underlying reason is making you feel constantly sleepy. 

Those who report feeling tired all the time, even after a good night’s sleep, could be experiencing fatigue, which can be more commonly known as exhaustion.

As Dr Sam Rodgers, general practitioner, and medical director of Medichecks, explains: “Everyone feels tired at the end of a busy day or a long flight or marathon training. Tiredness will ease after rest and recovery and does not stop you from what you are doing.

Exhaustion is when you are feeling drained, both physically and mentally, to the extent that you cannot carry out your normal activities at work or home.”

Medichecks' Advanced Tiredness and Fatigue Check offer an easy way to rule out some of the most common and treatable causes of fatigue. 

Here are some common reasons why you may be feeling fatigued: 

1.    Diabetes

Diabetes affects your body’s ability to control blood glucose levels. Glucose is the body’s primary fuel source. So, living with diabetes can change your body’s ability to use fuel effectively. Having too low or too high blood sugar, along with rises and falls in your blood sugar levels, can lead to feelings of fatigue.

2.    Low iron levels

Iron is a mineral with many body functions, such as forming new red blood cells, carrying oxygen around our body and strengthening our immune system. Low iron levels can lead to iron deficiency anaemia. This condition causes a reduction in red blood cells and a decrease in the amount of oxygen that your body can use. Low oxygen levels affect the body’s ability to generate energy, and a common symptom of this is fatigue. 

3.    Thyroid disease 

The thyroid is responsible for producing essential hormones which affect almost every cell in the body. The two main thyroid hormones are thyroxine (T4) and triiodothyronine (T3). An underactive thyroid (also known as hypothyroidism) occurs when the gland does not produce enough thyroid hormones, ultimately slowing down the body’s metabolism. Fatigue is a symptom of hypothyroidism.

4.    Low vitamin B12

Vitamin B12 is necessary to keep blood cells healthy and make DNA - the essential genetic material present in all our cells. Vitamin B12 is also a necessary vitamin for energy production. Low B12 levels can lead to anaemia and symptoms, including fatigue, feeling faint and headaches. 

5.    Low vitamin D

Many often refer to vitamin D as the ‘sunshine vitamin’. It is essential for maintaining healthy teeth and bones. Vitamin D is also involved in maintaining muscle strength. Many of us in the UK are vitamin D deficient. Deficiency can lead to symptoms such as muscle weakness and fatigue.

Many lifestyle factors can contribute to fatigue. As Dr Sam Rodgers explains, “There are obvious factors such as a lack of sleep, not eating well, smoking, not exercising or feeling over-stressed and trying to fit in too much.” 

You may therefore be able to improve your feelings of fatigue by making some healthy lifestyle changes. An excellent way to do this is to establish good sleep hygiene practices: avoid using your phone or watching TV an hour before you go to bed. Try doing relaxing activities instead, like having a warm bath and reading a book (but no thrillers!). Regular exercise can also improve your sleep quality. 

Our mental health can affect our feelings of energy and motivation, so it may be essential to address this. As Dr Sam explains, “It’s also important not to forget our emotional and psychological health. If there is no physical cause identifiable, then we would recommend talking through your symptoms with your GP.” Dr Sam adds that “If you have a busy lifestyle, make sure you give yourself some time off. Keep a couple of evenings and weekends free so that you can go home and relax.”

Medichecks' Advanced Tiredness and Fatigue Check offers an easy way to rule out some of the most common and treatable physical causes of fatigue. It includes a long-term measure of your body’s ability to control blood sugar (also known as HbA1c) along with a measure of your iron status. This test also measures your thyroid hormones to ensure your thyroid is working normally.