Fatigue

Free T3 may help your healthcare provider evaluate how well your thyroid is functioning at a cellular level. Some experts suggest it can reveal conversion issues that other thyroid tests might miss, potentially offering a more complete understanding of thyroid health.

Free T4 may help your healthcare provider determine whether your thyroid gland is producing adequate hormone levels. Some experts consider it one of the most informative markers for detecting both overactive and underactive thyroid conditions early.

The thyroid affects virtually every organ in your body. The hormones it produces (T3 and T4) regulate your metabolism, heart rate, body temperature, energy level, and even your mood. When thyroid function is disrupted, the effects can be wide-ranging. Hypothyroidism (underactive) is the most common thyroid condition, affecting an estimated 5% of adults, with a clear predominance in women. It is often caused by the autoimmune condition Hashimoto's disease. Symptoms develop gradually and are therefore often recognised late. Hyperthyroidism (overactive) is less frequent but can be more serious. Graves' disease is the most common cause. Untreated, it can lead to heart rhythm disorders and bone loss. For women trying to conceive, the TSH value is particularly relevant, as suboptimal thyroid function can affect fertility and pose risks during pregnancy. A TSH below 2.5 mU/L is often used as a target in this context.

Vitamin B12 is believed to be vital for healthy nerve cells, red blood cell formation, and DNA synthesis. Low levels may be associated with anaemia, fatigue, and neurological symptoms. Early detection through testing may help prevent long-term complications.

Adequate vitamin D levels are essential for strong bones, a well-functioning immune system, and overall well-being. Low levels may be associated with an increased risk of bone disorders, mood changes, and weakened immunity. Consult your healthcare provider for personalised advice.

Iron deficiency is the most common nutritional deficiency worldwide and one of the leading causes of fatigue. Ferritin detects iron deficiency at an early stage, before haemoglobin drops. This makes it a valuable preventive marker. In women of childbearing age, iron deficiency is particularly common due to menstrual blood loss. A ferritin below 30 µg/L with symptoms such as fatigue, concentration problems, or hair loss is often already reason to supplement, even if haemoglobin is still normal. On the other hand, significantly elevated ferritin (above 500 µg/L) can indicate haemochromatosis, a hereditary condition in which the body absorbs too much iron. Untreated, this can lead to liver, heart, and joint damage. Haemochromatosis occurs in 1 in 200 people of European descent and is often discovered late.

Type 2 diabetes affects more than one million people in the Netherlands, and an estimated 1.1 million more have prediabetes without knowing it. Untreated, diabetes significantly increases the risk of cardiovascular disease, kidney damage, eye problems, and nerve damage. Prediabetes is a reversible stage. With lifestyle adjustments — weight loss, more exercise, less sugar and processed carbohydrates — more than half of people with prediabetes can prevent developing diabetes. This makes early detection through a fasting glucose test or HbA1c very valuable.

HbA1c provides a long-term view of blood sugar control, unlike fasting glucose which reflects a single point in time. It is essential for diabetes diagnosis and management. Consult your healthcare provider.

The CBC is a cornerstone of preventive healthcare and diagnostic medicine. It can help detect a wide range of conditions including anemia, infections, immune disorders, blood cancers, and clotting problems. Regular CBC testing supports early detection and ongoing health monitoring.