What is reactive arthritis? Reactive arthritis happens when an infection causes joint pain and swelling. A bacterial infection in the digestive or urinary tract or the genitals usually triggers the condition, but arthritis symptoms typically do not start until a few weeks after you have recovered from the infection. The most common features of reactive arthritis are inflammation of the joints (especially the knees and ankles), eyes, and urinary tract, but not everyone gets all three, or they might not happen at the same time.

What is osteoarthritis? Osteoarthritis is a joint disease that happens when the tissues in the joint break down over time. It is the most common type of arthritis and is more common in older people. People with osteoarthritis usually have joint pain and, after rest, stiffness (inability to move easily) for a short period of time. The most commonly affected joints include the: Hands (ends of the fingers and at the base and ends of the thumbs). Knees. Hips. Neck. Lower back. Osteoarthritis affects each person differently. For some people, osteoarthritis does not affect day-to-day activities. For others, it causes

何謂骨關節炎？ 骨關節炎是一種關節疾病，是指關節內的組織隨著時間的推移而分解。這是最常見的關節炎類型，而且更常見於年長者。 骨關節炎患者通常有關節疼痛，而且在休息之後有短時間的關節僵直（難以移動）。最常累及的關節包括： 手（手指末端和拇指的起點和末端）。 膝蓋。 髖部。 頸部。 腰部。 骨關節炎對每個人的影響都有所不同。對有些人來說，骨關節炎不影響日常活動。而對其他人而言，骨關節炎會造成劇烈疼痛和殘障。

What is alopecia areata? Alopecia areata is a disease that causes hair loss. In alopecia areata, the immune system attacks the structures in skin that form hair (hair follicles). Alopecia areata usually affects the head and face, though hair can be lost from any part of the body. Hair typically falls out in small, round patches about the size of a quarter. In some cases, hair loss is more extensive.