There are many possible causes of your symptoms, including:

• An infection
  Examples include viral infections (especially Parvovirus, hepatitis B or hepatitis C and influenza), bacterial infections (such as Lyme disease, sexually transmitted disease, or a blood stream infection)
• An autoimmune disease
  These are conditions in which a person's immune system appears to normal tissues. Lupus is a good example but there are many others.
• Crystal-induced arthritis
  Gout and pseudogout are disorders in which crystals deposit in one or more joints. This causes pain, swelling and, in many cases, fever. However, these conditions usually affect only one or a few joints and are rare in pre-menopausal women.
• An allergic reaction
  For example, a reaction to a drug may cause fever and joint pain.

Of these, viral infections would be a common cause of the sudden symptoms you describe. Adults who develop parvovirus infection usually have some exposure to young children. This infection is most commonly seen among daycare workers or preschool teachers.

See your doctor for an evaluation. While many viral infections will go away without treatment, it's important to establish a diagnosis whenever possible. This may affect treatment and future screening.