Most medications do not prevent you from donating blood. Common medications such as those used to control blood pressure, birth control pills and over-the-counter medications do not affect your eligibility. If you have recently taken antibiotics, you must have completed the course prior to donating.
Yes, a tooth infection can cause a headache. Also, be aware that certain sinus conditions can mask as tooth problems.
Headaches also can be caused by clenching jaw muscles for long periods of time. Signs that may indicate a headache of dental origin include: 1  Pain behind the eyes. 2  Sore jaw muscles or tired muscles upon awaking. 3  Teeth grinding. 4  Clicking or popping jaw joints. 5  Head and/or scalp is painful to the touch. 6  Earaches or ringing in the ears.