Swelling
Most people with an ACL tear notice swelling of their knee joint. This is a mechanism of the body to repair the internal structures. It is often quite large and appears quickly, typically within a few minutes after the injury. Swelling mostly occurs in a partial ACL tear. Taking OTC painkillers or applying ice packs directly to the knee can provide temporary relief. Make sure to consult your healthcare provider to make a precise diagnosis. [4]
Redness
Right after a tear in the ACL, a condition called hemarthrosis may happen. It causes vessels feeding the ligament to fill the joint area with blood. As a result, you may notice redness and bruise in the affected knee. This means the knee may have a redder color than usual. In some cases, you do not notice this sign after the accident. But when it occurs during physical activity, it is definitely a sign of an ACL tear. [5]
