Overview
Blood circulates through blood vessels and the heart to support every organ in the body. Its main parts are plasma, which is the liquid portion, red blood cells, white blood cells, and platelets. Together, these parts transport oxygen and nutrients, remove waste products, help the immune system respond to threats, and support clotting when bleeding happens.
Key Symptoms
Blood itself does not cause symptoms, but blood-related disorders can. Warning signs may include unusual tiredness, pale skin, frequent infections, easy bruising, bleeding that is hard to stop, shortness of breath, or swelling and pain in a limb. Symptoms depend on which part of the blood is affected and how severe the problem is.
Causes and Risk Factors
Blood problems can happen for many reasons, including low iron or vitamin levels, infections, immune system conditions, inherited disorders, kidney disease, cancer, blood loss, or certain medicines. Dehydration can change the concentration of blood, and long periods of immobility can increase the risk of some blood clots. Family history, age, pregnancy, chronic illness, and tobacco use can also affect risk.
Who Is Affected
Everyone has blood and can develop blood-related conditions, but some groups are affected more often by certain problems. Children may be more likely to have inherited blood disorders recognized early in life. Older adults may have a higher risk of anemia, clotting problems, or blood cancers. People who are pregnant, menstruating, malnourished, or living with chronic disease may also be at higher risk for some blood conditions.
Prevention
Not all blood disorders can be prevented, especially inherited conditions. Some risks can be lowered by eating a balanced diet, staying active, avoiding tobacco, managing long periods of sitting, and getting recommended vaccines and medical care. Preventing severe blood loss, treating infections promptly, and following medical advice for chronic illnesses can also support blood health.
Diagnosis and Tests
Healthcare professionals often use blood tests to learn about blood health. Common tests include a complete blood count, blood smear, clotting tests, blood chemistry tests, and tests for iron, vitamins, infection, or immune problems. In some cases, imaging, genetic testing, or bone marrow testing may be needed to understand the cause of a blood disorder.
Treatment Categories
Treatment depends on the specific condition and its cause. Broad categories include nutritional support, treatment of infections or underlying diseases, medicines that affect clotting or immunity, blood transfusion, and specialized care for inherited or cancer-related blood disorders. Ongoing monitoring is often important because blood conditions can change over time.
Diet and Lifestyle
A varied diet that includes enough iron, vitamin B12, folate, and protein helps the body make healthy blood cells. Drinking enough fluids supports circulation, and regular movement can help lower the risk of some blood clots. Avoiding tobacco and limiting exposure to toxins may also support blood and vessel health.
When to Seek Medical Care
Seek medical care if you have unusual tiredness, repeated infections, unexplained bruising, frequent nosebleeds, blood in urine or stool, very heavy menstrual bleeding, or swelling and pain in an arm or leg. Medical review is also important for ongoing paleness, shortness of breath, or symptoms that do not improve. If you have a known blood disorder, follow-up care is important even when symptoms seem mild.
When It May Be an Emergency
Get emergency help right away for severe bleeding, coughing or vomiting blood, chest pain, sudden trouble breathing, fainting, signs of stroke, or sudden one-sided swelling and pain with shortness of breath. These can be signs of major blood loss, a dangerous clot, or another urgent condition. Emergency care is also needed for high fever with confusion or a very unwell appearance.