Deer ticks can be so small that they are almost impossible to see. Since many people never realize they were bitten by a tick, they may never realize their symptoms could be Lyme disease.
The first sign of infection is usually a red circular rash that is flat or slightly raised. The rash usually appears at the site of the tick bite 3 to 30 days after infection. The rash usually expands over several days. The center of the rash may appear clear as it enlarges, resulting in a bull's-eye appearance.
Other symptoms that may develop with Lyme disease include:
Joint inflammation in the knees and other large joints
Unusual or strange behavior
If Lyme disease is left untreated, it may spread to other parts of the body, causing another set of symptoms within a few days to weeks. The symptoms of untreated Lyme disease include:
Loss of muscle tone on one or both sides of the face
Sever headaches and neck stiffness due to meningitis
Shooting pains that may interfere with sleep
Heart palpitations and dizziness due to heartbeat changes
Pain that moves from joint to joint.
After several months of untreated Lyme disease, about 60% of people will begin to have intermittent bouts of arthritis with severe joint pain and swelling. Up to 5% of those with untreated Lyme disease develop chronic neurological complaints months to years after infection, such as shooting pains, numbness or tingling in the hands or feet, and problems with concentration and short term memory.