If Lyme disease goes unnoticed or does not respond to treatment, you may eventually develop joint problems, weakness or numbness in the arms or legs, severe fatigue, or difficulties with memory and thinking. These symptoms can resemble those of other illnesses such as:

• Arthritis, a condition that causes inflammation of a joint. Symptoms of arthritis may include pain, swelling, redness, heat, and limitation of movement.
• Juvenile rheumatoid arthritis (JRA), a childhood disease that causes joint inflammation and swelling. Affected joints are often stiff and painful.
• Fibromyalgia, which causes widespread muscle and soft tissue pain and tenderness, especially in the trunk, neck, and shoulders.
• Chronic fatigue syndrome, which causes severe fatigue that interferes with daily living.
• Multiple sclerosis, which causes problems with muscle control and strength, vision, balance, sensation, and mental functions.