The German Heart Foundation has issued a warning about the serious health risks associated with thickened blood, a condition medically known as polycythaemia. This disorder occurs when the blood contains an abnormally high number of red blood cells, increasing its viscosity and making it harder to circulate through the arteries. As a result, the heart must work significantly harder, raising the risk of potentially fatal complications such as blood clots, heart attacks, and strokes.
What Causes Thick Blood?
According to the Foundation, polycythaemia may arise as a primary condition—often due to genetic predisposition or heavy smoking—but it can also be a secondary indicator of underlying health issues. Potential causes include:
Impaired oxygen delivery due to decreased blood oxygenation
Chronic digestive inflammation or food intolerances
Dehydration
Heart conditions such as valve defects or heart failure
Bone marrow disorders
Respiratory diseases like chronic obstructive pulmonary disease (COPD) or bronchial asthma
Certain types of cancer
Recognising the Symptoms
Several symptoms can signal an increase in blood thickness, including:
Deep facial redness
Persistent headaches
Dizziness or light-headedness
Ringing in the ears (tinnitus)
Elevated blood pressure
Widespread itching
Anyone experiencing these symptoms is strongly advised to consult a healthcare provider promptly. A simple blood test can help measure red blood cell concentration and assess the blood’s overall thickness.
Doctors often evaluate the hematocrit level—the proportion of red blood cells in total blood volume—as a key diagnostic marker. Normal hematocrit levels typically range from 37% to 45% in women and 42% to 50% in men. In cases of thickened blood, this value can rise significantly, often exceeding 50%.
