What your constant fatigue REALLY means – and when it’s a sign of killer disease 

IT'S normal to feel tired from time to time.

But if you find yourself in a debilitating state of exhaustion – suffering a constant lack of energy both physically and mentally – it could be time to investigate the cause.

Understanding the difference between tiredness and fatigue is key.

While tiredness and fatigue both describe low energy, fatigue is a persistent feeling of tiredness that doesn't just go away with rest.

Not getting enough sleep is the most common cause of tiredness.

However, the causes of fatigue can reach far beyond poor bedtime habits.

Dr Jonathan Webster, a Doctify-rated GP, said there are many other things that can cause fatigue.

“Lifestyle factors can be one of the causes,” he explained.

“Poor diet, for example eating highly processed foods, foods high in sugars, and carbonated drinks, excessive nocturnal screen time and gaming, disturbed diurnal rhythms, excessive alcohol use, recreational drug use, and not getting enough regular exercise can all lead to fatigue.

“Other common causes are medical conditions, such as anaemia, diabetes, heart disease, thyroid disorders, chronic infection, and chronic pain conditions.

“And mental health issues like depression, anxiety and stress also.”

Fatigue can negatively affect work performance, social interactions, and overall quality of life.

But Dr Webster said there are some things you can try to help:

• Improve sleep habits: Ensure you get enough restful sleep. Drinking alcohol will impact the quality of your sleep.
• Exercise regularly: Physical activity can boost energy levels.
• Stay hydrated: Drink plenty of water to avoid dehydration.
• Eat a balanced diet: Include nutrient-rich foods in your meals avoiding too much processed foods.
• Manage stress: Practice relaxation techniques like yoga, mediation, breathing exercises, regular walks and exercise.

Could a vitamin deficiency be causing you fatigue?

Vitamin deficiencies are another significant cause of fatigue – with the most common ones to blame being vitamin D, vitamin B12 and iron.

Known as the ‘sunshine vitamin', vitamin D helps regulate the amount of calcium and phosphate in the body.

But the body only creates it when direct sunlight touches the skin while you're outdoors.

Between October and early March we don't make enough vitamin D from sunlight.

And being deficient can lead to muscle weakness, fatigue and aching bones, warned Dr Webster.

During spring and summer he recommends increasing sun exposure to at least 20 minutes a day, and consuming foods fortified with vitamin D and taking a supplement during autumn and winter.

Vitamin B12 is essential for energy production and the function of muscles.

A lack of it can cause a wide range of symptoms, including neurological problems like muscle weakness, which can be linked to tiredness, said Dr Webster.

But he advised: “Eating more meat can help (although too much red meat in particular can cause other health issues), as well as dairy products, and taking B12 supplements.”

Iron is essential for forming red blood cells and carrying oxygen throughout the body, supporting healthy muscle function, immune system function, and overall growth and development.

Low iron levels can result in anaemia – a condition where your blood doesn't have enough healthy red blood cells, leading to reduced oxygen transport to the body's tissues, causing symptoms like tiredness and weakness.

Dr Webster said: “Include iron-rich foods like red meat (same health warning as before) beans, and dark green vegetables in your diet.

“You may need to take iron supplements if your body's stores of iron are low.”

Vitamin deficiencies can be tested for by a simple blood test taken by your GP.

Many vitamin deficiencies can be addressed by improving your diet or taking supplements, but it's always best to get the advice of your doctor first.

Can fatigue mean cancer?

Fatigue is more commonly caused by the reasons above, but in some cases can indicate certain cancers – particularly blood cancers like leukaemia and lymphoma, says Dr Webster.

He added: “It can also be associated with cancers affecting the gastrointestinal system, such as stomach and bowel cancer.

“Cancer-related fatigue is often described as a profound, whole-body exhaustion that doesn't improve with rest.

“It can be physical, emotional, and mental, making it difficult to perform daily tasks.

“But fatigue is a very non-specific symptom and it is more likely to have other causes rather than a cancer.”

When to see your GP

If your fatigue is accompanied by other symptoms like fever, shortness of breath, or loss of appetite, it's important to see your doctor, said Dr Webster.

If there's no obvious lifestyle cause then get assessed by your GP – having some simple blood tests and being examined should identify what's leading to your constant lack of energy.

Dr Webster added: “Most patients that I see who present with fatigue or are ‘tired all the time' do not have anything seriously wrong with them.

“Just living a busy life in itself can be fatiguing!”

Try the following sleep tips below to help you identify if you have tiredness or fatigue…