Can you tell by the symptoms how far lyme disease may have progressed?

Lyme disease: As the bacteria spread in the skin away from the initial tick bite, the infection causes an expanding reddish rash that is often associated with "flu-like" symptoms. Later, it can produce abnormalities in the joints, heart, and nervous system.

Not always.: Lyme disease is insidious, and it is not at all uncommon for long periods of time to go by with no symptoms of any kind. It may not even be clear from blood tests, but lab testing is almost always a more accurate way of staging the disease than relying on clinical symptoms.