What it is
Thicker blood can raise the risk of blood clots, so the cause and level are checked carefully.
Treatment depends on the cause and may include stopping smoking, treating sleep apnoea, adjusting medicines, removing blood (venesection), or medicines for bone marrow conditions.
Common signs
- Often no symptoms
- Headaches and dizziness
- Tiredness
- Red skin, especially on the face
- Itching after a warm bath
How it is usually diagnosed
- Full blood count repeated
- Tests for a cause, such as oxygen levels and kidney tests
- JAK2 gene test for polycythaemia vera
Records worth keeping
Keeping these together makes each appointment easier, especially when you see a new doctor:
- Haemoglobin and haematocrit results over time
- JAK2 and other test results
- Dates of venesection
- Haematology letters
Questions to ask your doctor
- What is causing the high red cell count?
- Do I need treatment to lower it?
- How can I reduce my risk of clots?
When to get help right away
Call 112 or go to the nearest emergency department if you have:
- Signs of a blood clot or stroke: chest pain, sudden breathlessness, a swollen painful leg, face drooping or arm weakness: call 112
This page is general information. It is not a diagnosis and does not replace a doctor who knows your history. Medfold keeps your records organised; it does not interpret them.