If you have a myeloproliferative neoplasm (MPN), you might feel lost in a world of unfamiliar words and concepts.
Hematologists are doctors specializing in blood diseases, but their language can be hard to follow. We created this blog to help you understand your condition better. Here you will find clear explanations of terms and concepts related to MPNs.
Content guide
What exactly is blood?
Blood is a vital fluid that circulates throughout your body, carrying oxygen and nutrients to your organs and tissues and removing waste products and carbon dioxide. Blood also helps fight infections, heal wounds, and regulate body temperature. Blood comprises four main components: plasma, red blood cells, white blood cells, and platelets.
Plasma is the liquid part of blood, making up about 55% of its volume. It contains water, proteins, hormones, vitamins, minerals, and other essential substances for your body's functions.
Red blood cells (RBCs) are the most abundant cells in your blood, making up about 45% of its volume. They contain a protein called hemoglobin that binds to oxygen and gives blood its red color. RBCs transport oxygen from your lungs to your tissues and organs and bring back carbon dioxide to be exhaled.
White blood cells (WBCs) are the cells that protect your body from infections and diseases. They make up less than 1% of your blood volume but are essential for your immune system. There are different types of WBCs, each with a specific role in fighting bacteria, viruses, fungi, parasites, and cancer cells.
Platelets are the smallest cells in your blood, making up less than 1% of its volume. They are responsible for clotting your blood when you have a cut or an injury. They stick together to form a plug that stops bleeding and helps heal the wound.
What do blood cells do?
Blood cells perform many functions that are essential for your health and well-being. Some of the main parts are:
Red blood cells deliver oxygen to your tissues and organs, which need it to produce energy and function properly. Without enough oxygen, you may feel tired, weak, dizzy, or short of breath.
White blood cells defend your body from infections and diseases by recognizing and destroying foreign invaders such as bacteria, viruses, fungi, parasites, and cancer cells. Without enough WBCs, you may be more prone to infections or harder to fight them off.
Platelets help stop bleeding and heal wounds by forming clots that seal the damaged blood vessels. Without enough platelets, you may bleed more easily or excessively from minor cuts or bruises.
Where do blood cells come from?
Blood cells are produced in your bone marrow, the soft tissue inside some of your bones. Bone marrow contains stem cells that can develop into different types of blood cells depending on the signals they receive from your body. Your body constantly makes new blood cells to replace the old ones that die or get used up.
What are MPNs?
MPNs are a group of rare blood cancers that affect the production of blood cells in your bone marrow. In MPNs, some stem cells in your bone marrow become abnormal and start making too many or too few blood cells of one or more types. This can cause various problems, such as anemia (low RBCs), infections (low WBCs), bleeding (low platelets), or thrombosis (high platelets or RBCs).
There are three main types of MPNs: polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis (MF). Each class has different symptoms and complications depending on which type of blood cell is affected.
PV is a condition where your bone marrow makes too many RBCs. This causes your blood to become thicker and slower to flow through your vessels. This can lead to headaches, dizziness, itching, fatigue, or vision problems. It can also increase your risk of developing blood clots in your veins or arteries that can cause serious issues such as stroke or heart attack.
ET is a condition where your bone marrow makes too many platelets. This causes your blood to become more sticky and prone to clotting. This can lead to symptoms such as tingling or numbness in your hands or feet, burning or redness in your skin, or ulcers on your fingers or toes. It can also increase your risk of developing blood clots in your veins or arteries that can cause serious problems such as stroke or heart attack.
MF is a condition where your bone marrow becomes scarred and fibrous due to the abnormal growth of stem cells.