Knee effusion - wikipedia Knee effusion This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations. Please help to improve this article by introducing more precise citations. ( February 2015 ) Knee effusion A traumatic right knee effusion ; note the swelling lateral to the kneecap as marked by the arrow Classification and external resources ICD - 10 M25. 4 ICD - 9 - CM 719.0 DiseasesDB 15237 ( edit on Wikidata ) Knee effusion or swelling of the knee ( colloquially known as water on the knee ) occurs when excess synovial fluid accumulates in or around the knee joint. There are many common causes for the swelling, including arthritis, injury to the ligaments or meniscus, or fluid collecting in the bursa, a condition known as prepatellar bursitis. Contents 1 Signs and symptoms 1.1 Pain 1.2 Swelling 1.3 Stiffness 1.4 Bruising 2 Causes 3 Diagnosis 3.1 Joint aspiration 3.2 Imaging 3.3 MRI 3.4 Blood tests 4 Treatment 5 References Signs and symptoms Signs and symptoms of water on the knee depend on the cause of excess synovial fluid build - up in the knee joint. These may include : Pain Osteoarthritis knee pain usually occurs while the joint is bearing weight, so the pain typically subsides with rest ; some patients suffer severe pain, while others report no discomfort. Even if one knee is much larger than the other, pain is not guaranteed. Swelling One knee may appear larger than the other. Puffiness around the bony parts of the knee appear prominent when compared with the other knee. Stiffness When the knee joint contains excess fluid, it may become difficult or painful to bend or straighten. Fluid may also show under the knee when straightened. Icing may help to decrease swelling. Heat may help relax the muscles of the knee. Bruising If an individual has injured his or her knee, he or she may note bruising on the front, sides or rear of the knee. Bearing weight on the knee joint may be impossible and the pain unbearable. bruising may be seen as bluish lesion. Causes Causes of the swelling can include arthritis, injury to the ligaments of the knee, or an accident after which the body 's natural reaction is to surround the knee with a protective fluid. There could also be an underlying disease or condition. The type of fluid that accumulates around the knee depends on the underlying disease, condition or type of traumatic injury that caused the excess fluid. The swelling can, in most cases, be easily cured. Underlying diseases may include Knee osteoarthritis Rheumatoid arthritis Infection Gout Pseudogout Prepatellar bursitis ( kneecap bursitis ) Cysts Tumours Repetitive strain injury Having osteoarthritis or engaging in high - risk sports that involve rapid cut - and - run movements of the knee -- football or tennis, for example -- means an individual is more likely to develop water on the knee. In overweight or obese individuals the body places more weight on the knee joint. This causes more wear in the joint. Over time, the body may produce excess joint fluid. Diagnosis Diagnostic tests include : Skyline view of the patella demonstrating a large joint effusion as marked by the arrow Joint aspiration Also known as arthrocentesis, this procedure includes withdrawal of fluid from inside the knee for analysis such as cell count, culture for bacteria, and examination for crystals, such as uric acid or calcium pyrophosphate dihydrate ram crystals found in gout or pseudogout. Imaging X-ray of the knee of a 12 year old male, showing knee effusion of medium severity, marked by black arrows. It displaces the patella anteriorly and extends into the suprapatellar bursa. An X-ray is useful to verify that there is no break or dislocation when there is a history of trauma. May show signs of osteoarthritis. Mri Magnetic Resonance Imaging detects abnormalities of the bone or knee joint, such as a tear in the ligaments, tendons or cartilage. Blood tests If the knee is swollen and red and warm to the touch when compared to the other knee, a doctor may be concerned about inflammation due to rheumatoid arthritis or a crystalline arthritis, such as gout or pseudogout, or joint infection. Besides sending the joint fluid to a laboratory for analysis, blood tests may requested to determine a white blood cell count, erythrocyte sedimentation rate, and perhaps the level of C - reactive protein or uric acid. If blood tests reveal Lyme disease antibodies forming, the condition may be attributed to it. Treatment Treatment of fluid in the knee depends on the underlying cause of the swelling. General measures such as rest, ice, and analgesics such as acetaminophen ( paracetamol ) and NSAIDS are often recommended. Chymotrypsin, trypsin and Diclofenac are also recommended. References Mayo Clinic - Water on the Knee Medicine Outline History Specialties and subspecialties Surgery Cardiac surgery Cardiothoracic surgery Colorectal surgery Eye surgery General surgery Neurosurgery Oral and maxillofacial surgery Orthopedic surgery Hand surgery Otolaryngology ( ENT ) Pediatric surgery Plastic surgery Reproductive surgery Surgical oncology Thoracic surgery Transplant surgery Trauma surgery Urology Andrology Vascular surgery Internal medicine Allergy / Immunology Angiology Cardiology Endocrinology Gastroenterology Hepatology Geriatrics Hematology Hospital medicine Infectious disease Nephrology Oncology Pulmonology Rheumatology Obstetrics and gynaecology Gynaecology Gynecologic oncology Maternal -- fetal medicine Obstetrics Reproductive endocrinology and infertility Urogynecology Diagnostic Radiology Interventional radiology Nuclear medicine Pathology Anatomical pathology Clinical pathology Clinical chemistry Clinical immunology Cytopathology Medical microbiology Transfusion medicine Other specialties Addiction medicine Adolescent medicine Anesthesiology Dermatology Disaster medicine Diving medicine Emergency medicine Mass - gathering medicine Family medicine General practice Hospital medicine Intensive - care medicine Medical genetics Neurology Clinical neurophysiology Occupational medicine Ophthalmology Oral medicine Pain management Palliative care Pediatrics Neonatology Physical medicine and rehabilitation ( PM&R ) Preventive medicine Psychiatry Public health Radiation oncology Reproductive medicine Sexual medicine Sleep medicine Sports medicine Transplantation medicine Tropical medicine Travel medicine Venereology Medical education Medical school Bachelor of Medicine, Bachelor of Surgery Bachelor of Medical Sciences Master of Medicine Master of Surgery Doctor of Medicine Doctor of Osteopathic Medicine MD -- PhD Related topics Allied health Dentistry Podiatry Physiotherapy Nanomedicine Molecular oncology Personalized medicine Veterinary medicine Physician Chief physician History of medicine Book Retrieved from `` https://en.wikipedia.org/w/index.php?title=Knee_effusion&oldid=817139567 '' Categories : Musculoskeletal disorders Knee injuries and disorders Hidden categories : Articles lacking in - text citations from February 2015 All articles lacking in - text citations Infobox medical condition Talk Contents About Wikipedia Deutsch Edit links This page was last edited on 26 December 2017, at 12 : 00. 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Question: where does fluid on the knee come from
Answer: depends on the underlying disease, condition or type of traumatic injury