Always Tired? Blood Tests That Could Help Find The Cause

Feeling tired all the time can be frustrating and affect every aspect of your life.

Many people assume tiredness is simply due to a busy lifestyle, stress or poor sleep. While these can certainly contribute, persistent fatigue may sometimes be linked to an underlying health issue.

Blood testing can help identify common causes and provide valuable information about your overall health.

When Is Tiredness Worth Investigating?

Occasional tiredness is normal.

However, you should consider further investigation if:

Fatigue persists for several weeks
You wake up feeling exhausted
Your energy levels continue to decline
You struggle to complete normal daily activities
Tiredness is affecting work, family life or exercise

Common Causes of Fatigue

There are many potential causes, including:

Iron deficiency
Vitamin D deficiency
Vitamin B12 deficiency
Thyroid disorders
Diabetes
Hormonal imbalances
Chronic inflammation
Poor nutrition
Stress and anxiety
Sleep disorders

Because symptoms often overlap, blood testing can help identify possible contributing factors.

Low iron stores can contribute to fatigue. Learn more in our guide: What Is Ferritin and Why Does It Matter?

Iron Deficiency and Low Ferritin

Iron is essential for carrying oxygen around the body.

Low iron stores can cause:

Fatigue
Shortness of breath
Poor concentration
Dizziness
Headaches

A ferritin blood test can assess your body’s iron stores and may help identify iron deficiency before anaemia develops.

Vitamin D Deficiency

Vitamin D deficiency is extremely common in the UK.

Symptoms may include:

Tiredness
Muscle aches
Low mood
Frequent infections
General weakness

Testing can determine whether your vitamin D levels are within the recommended range.

Vitamin B12 Deficiency

Vitamin B12 plays an important role in energy production and nervous system function.

Low levels may cause:

Fatigue
Brain fog
Tingling sensations
Poor memory
Low mood

People following vegetarian or vegan diets may be at increased risk.

Thyroid Problems

Your thyroid gland helps regulate metabolism.

An underactive thyroid may cause:

Fatigue
Weight gain
Dry skin
Hair thinning
Feeling cold

A thyroid blood test can help assess thyroid function.

Blood Sugar Problems

Both diabetes and pre-diabetes can contribute to tiredness.

Symptoms may include:

Increased thirst
Frequent urination
Blurred vision
Fatigue

HbA1c testing can help assess average blood sugar levels over the previous few months.

Inflammation and General Health

Sometimes tiredness may be linked to underlying inflammation or infection.

Markers such as CRP can provide additional information about your health and may help guide further investigations.

Which Blood Test Is Best?

The most suitable test depends on your symptoms.

Many patients choose a comprehensive health screen that includes:

Full Blood Count
Iron Studies
Ferritin
Vitamin D
Vitamin B12
Thyroid Function
HbA1c
Kidney Function
Liver Function

This provides a broader picture of overall health.

Blood Testing at Veritas Pharmacy

Veritas Pharmacy offers convenient private blood testing appointments in Sunderland.

We provide:

Same-day appointments where available
Professional sample collection
Rapid testing options for selected markers
Comprehensive health screening profiles
Clear results and follow-up guidance

Take Control of Your Health

If you have been feeling tired for weeks or months, blood testing may help identify a possible cause.

Book a blood test at Veritas Pharmacy and take the first step towards understanding your symptoms.