Hemarthrosis

Hemarthrosis is a bleeding into joint spaces. It is a common feature of hemophilia.

Hemarthrosis
Other names	Haemarthrosis
Lipohemarthrosis (blood and fat in the joint space) seen in a person with a subtle tibial plateau fracture. The arrow indicates a fluid level between the upper fat component and the lower blood component.
Medical specialty	Rheumatology
Symptoms	Joint pain, swelling, and redness

Blood tests

Synovial fluid examination^[1][2]

Type	WBC (per mm3)	% neutrophils	Viscosity	Appearance
Normal	<200	0	High	Transparent
Osteoarthritis	<5000	<25	High	Clear yellow
Trauma	<10,000	<50	Variable	Bloody
Inflammatory	2,000–50,000	50–80	Low	Cloudy yellow
Septic arthritis	>50,000	>75	Low	Cloudy yellow
Gonorrhea	~10,000	60	Low	Cloudy yellow
Tuberculosis	~20,000	70	Low	Cloudy yellow
Inflammatory: Arthritis, gout, rheumatoid arthritis, rheumatic fever