It is not possible to establish a diagnosis for your knee pain without an in-person consultation, as there are a number of questions as well as an in-person physical exam which are necessary to establish a firm diagnosis.
Perhaps the most common cause of knee pain is osteoarthritis
, a degenerative disease of the bones and cartilage. It predominantly affects older individuals as it is a disease of "wear-and-tear," but can affect younger individuals as well, particularly obese persons whose additional weight puts strain on their knees. Gout
can also cause knee pain, redness and swelling, particularly in older individuals who drink large amounts of alcohol and eat a diet high in fatty foods. A rarer cause of knee pain, particularly pain associated with swelling and redness which is worse in the mornings and improves with exercise is "inflammatory arthritis," a name for an aggressive group of causes of arthritis mediated by an inappropriate response of the body's immune system. Finally, infections can cause arthritis which is painful, red, swollen and often associated with fevers.
You should definitely seek an in-person consultation for this knee pain, as several of the diagnoses above, while rare, can cause irreversible damage to the knees, and cannot be diagnosed without an in-person consultation.