Thin blood: Causes, symptoms, and treatment Health ConditionsHealth ConditionsAlzheimer's & DementiaAnxietyArthritisAsthma & AllergiesBreast CancerCancerCardiovascular HealthCOVID-19Dermatology & SkincareDiabetesEnvironment & SustainabilityExercise & FitnessEye HealthHeadache & MigraineHealth EquityHIV & AIDSHuman BiologyInflammatory Bowel DiseaseLeukemiaLGBTQIA+Men's HealthMental HealthMultiple Sclerosis (MS)NutritionParkinson's DiseasePsoriasisSexual HealthWomen's HealthDiscoverNewsLatest NewsOriginal SeriesMedical MythsHonest NutritionThrough My EyesNew Normal HealthPodcastsHow to understand chronic painWhat is behind vaccine hesitancy?The amazing story of hepatitis C, from discovery to cureNew directions in dementia researchCan psychedelics rewire a depressed, anxious brain?Why climate change matters for human healthToolsGeneral HealthDrugs A-ZHealth HubsHealth ToolsBMI Calculators and ChartsBlood Pressure Chart: Ranges and GuideBreast Cancer: Self-Examination GuideSleep CalculatorHealth ProductsAffordable Therapy OptionsBlood Pressure MonitorsDiabetic SuppliesFitness TrackersHome GymsGreen Cleaning ProductsHow to Shop for CBDQuizzesRA Myths vs FactsType 2 Diabetes: Managing Blood SugarAnkylosing Spondylitis Pain: Fact or FictionConnectAbout Medical News TodayWho We AreOur Editorial ProcessContent IntegrityConscious LanguageNewslettersSign UpFollow UsMedical News TodayHealth ConditionsDiscoverToolsConnectSubscribe Everything you need to know about thin bloodMedically reviewed by Danielle Hildreth, RN, CPT — By Jo Lewin R.N. — Updated on September 25, 2022Thin blood means having too few platelets, a part of the blood that helps it clot. Thin blood typically does not cause symptoms but can lead to excessive bleeding and bruising. Blood contains four main components: plasma, red blood cells, white blood cells, and platelets. Platelets are small cells that clump together and help blood clot. Thin blood occurs when a person has a low number of platelets. Doctors refer to the condition as thrombocytopenia. The normal level of platelets in the blood is between 150,000–450,000 per milliliter (mL). If levels of platelets fall below 150,000/mL, it may indicate thin blood. This article will look at the causes of thin blood, the symptoms, and what a person can do about it. Causes Share on PinterestAitor Diago/Getty ImagesThe body creates platelets in bone marrow and stores an amount of them in the spleen. A range of factors may cause a low platelet count, including the following: Decreased platelet production Viral infections, such as HIV, hepatitis C, mumps, rubella, or the Epstein-Barr virus, may cause platelet numbers to fall. Bone marrow disorders, such as leukemia and lymphoma, can also affect how many platelets the body can produce. Medication Some people take blood-thinning medications to reduce their risk of heart attack and stroke. Two main types of medication thin the blood are anticoagulants and antiplatelet drugs. These medications impair blood clot formation but can also decrease platelet levels. Examples include:heparinnonsteroidal anti-inflammatory drugs, such as aspirinstatinscancer treatments such as tamoxifen Disorders of the spleen The spleen produces platelets, so problems with the spleen can cause thin blood. Conditions that affect the spleen include:splenomegaly, or enlarged spleenhypersplenism, which may cause platelets to get trapped in the spleen Increased breakdown of platelets Certain autoimmune conditions, such as systemic lupus erythematosus (SLE), can increase the rate of platelet destruction. If the body does not make new platelets fast enough, a person may have thin blood. Chronic liver disease CLD CLD lowers thrombopoietin levels, which is the hormone responsible for stimulating platelet production. Low thrombopoietin levels reduce the rate at which the body produces platelets. Other factors There are also some physiological variables that affect platelet count:Aging: Platelet numbers may become lower as a person ages.Genetics: Some people have low platelet counts due to genetic factors.Pregnancy: Low platelet counts affect close to 10% of pregnant people at the time of birth. Symptoms Symptoms of thin blood include:slow wound clottingbleeding gumsnosebleedsblood in the stoolsheavy menstrual flow without clots Occasionally, a person with thin blood may also be prone to sudden bruising, known as purpura, or pinprick hemorrhages on the skin, known as petechiae. Some people may not experience any symptoms. Diagnosis A doctor can diagnose thin blood by looking at platelet numbers in a complete blood count or CBC. When talking with a doctor, it is essential for a person to tell them about any medications or supplements that might be causing thin blood. These include over-the-counter painkillers, such as aspirin. Thin blood vs thick blood Thin blood presents problems with clotting, wound healing, and bruising. On the other hand, thick blood can increase the risk of blood clots and thrombosis, which can be life threatening. Risk factors for thick blood include:geneticsobesitychronic inflammationinsulin resistance and diabetesdietary choices, such as consuming too much cholesterol Polycythemia is a condition that causes blood to thicken due to high numbers of red blood cells. Doctors can prescribe anticoagulant medications, such as heparin and warfarin, when blood is thick and a person has an increased risk of blood clots, stroke, or heart attack. Treatment Treatment for thin blood will depend on the underlying cause. However, sometimes treating the underlying cause may not change the platelet count, and the blood will remain thin. On occasions, doctors will prescribe corticosteroids to treat thin blood in conditions such as idiopathic thrombocytopenic purpura (ITP). In severe cases, they may recommend a platelet transfusion. When to contact a doctor It is crucial to contact a doctor for a diagnosis if a person has symptoms that might indicate thin blood. A doctor can help determine the underlying cause and develop a personalized treatment plan. They can also advise a person on how to take precautions and manage problems caused by thin blood, including excessive bleeding. Frequently asked questions Below are some frequently asked questions about thing blood. What happens when your blood is thin When a person’s blood has a low level of platelets, it will not clot as it should. This can lead to excessive bruising and heavy bleeding. Can drinking water thin your blood Dehydration can cause blood to thicken and blood vessels to constrict. Maintaining adequate hydration levels helps keep blood at an optimum thickness and is essential for overall good health. It is possible to overhydrate by drinking too much water, although this is uncommon. Summary The medical term for thin blood is thrombocytopenia. This occurs when there are low levels of platelets in the blood. Platelets are small cells that clump together to form clots. Having low platelet levels does not normally cause symptoms but can lead to excessive bleeding and easy bruising. Viral infections, spleen disorders, medications, and other chronic conditions can all cause low platelet levels. Treatment for thin blood will depend on its underlying cause. Last medically reviewed on September 25, 2022Blood / Hematology 10 sourcescollapsedMedical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations. We avoid using tertiary references. We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.Bakchoul, T., et al. (2018). Drug-associated thrombocytopenia.https://ashpublications.org/hematology/article/2018/1/576/277620/Drug-associated-thrombocytopeniaImmune thrombocytopenia. (2022).https://rarediseases.org/rare-diseases/immune-thrombocytopenia/Jinna, S., et al. (2022). Thrombocytopenia.https://www.ncbi.nlm.nih.gov/books/NBK542208/Lv, Y., et al. (2016). Hypersplenism: History and current status.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5038876/Mitchell, O., et al. (2016). The pathophysiology of thrombocytopenia in chronic liver disease.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847598/Platelet disorders: Thrombocytopenia. (2022).https://www.nhlbi.nih.gov/health/thrombocytopeniaPolycythaemia. (2019).https://www.nhs.uk/conditions/polycythaemia/Raadsen, M., et al. (2021). Thrombocytopenia in virus infections.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7924611/Reese, J. A., et al. Platelet counts during pregnancy.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6049077Understand your risk of excessive blood clotting. (n.d.).https://www.heart.org/en/health-topics/venous-thromboembolism/understand-your-risk-for-excessive-blood-clottingFEEDBACK:Medically reviewed by Danielle Hildreth, RN, CPT — By Jo Lewin R.N. — Updated on September 25, 2022 Latest newsWhat sets 'SuperAgers' apart? Their unusually large neuronsOmega-3 may provide a brain boost for people in midlifeSeasonal affective disorder (SAD): How to beat it this fall and winterCDC: Monkeypox in the US 'unlikely to be eliminated in the near future'Why are more women prone to Alzheimer's? New clues arise Related CoverageWhat to know about pancytopenia Pancytopenia is when a person's red and white blood cells and platelets are low. There is a range of symptoms and causes.READ MOREHow to increase hemoglobin: Home remediesMedically reviewed by Daniel Murrell, MD A variety of conditions and lifestyle factors can lead to a reduction in hemoglobin. Common causes include anemia, pregnancy, and thyroid conditions…READ MOREWhat are the causes of a low platelet count?Medically reviewed by Meredith Goodwin, MD, FAAFP A low platelet count is a blood disorder that can sometimes be severe. Learn about the many possible causes of a low count, as well as the symptoms…READ MOREWhat to know about anticoagulant medicationsMedically reviewed by Alexandra Perez, PharmD, MBA, BCGP Anticoagulants are medications that prevent the blood from clotting. This reduces the chance of blood clots. Learn more here.READ MORE