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.
Toothache can cause other body sickness and pain such as fever, body pain, muscle pain, headaches, and swollen glands in the neck, sinuses, mouth sores, jaw pains, abscess, gum diseases, bitter taste in the mouth, cold like flu, dry mouth, oral cancer, tooth sensitivity and stinky breath (halitosis).