5. Lyme Disease
Very tiny ticks infected with very nasty bacteria pass on Lyme disease while sucking up a blood dinner. You may not even notice the tick, but you will notice the resulting infection. The early infection involves headaches, muscle and joint pain, and other flu-like symptoms. As it progresses, headaches increase along with severe joint pain and swelling and shooting pains in hands and feet. Lyme disease requires special testing to identify.