What can cause a headache on one side and my eye bloodshot in same place?

Many headaches. There are a number of unilateral headaches associated with cranial autonomic symptoms which can cause redness of the eye on the same side including migraine, cluster, hemicrania continua, paroxysmal hemicrania, and sunct. Diagnosis depends upon other features of the headache, most importantly duration of the headache without treatment as well as frequency.

Related Questions

What causes a headache on one side and my eye bloodshot in same area?

Depends. There are multiple possibilities. Some forms of migraine headache can present that way; however, i would recommend you be seen by an ophthalmologist to evaluate for possible eye problems. Read more...

What could cause bloodshot eyes and headaches all of the sudden?

Many causes. Difficult to say. There are many causes of headaches, from mild neck muscle strain and tension to life-threatening medical issues. Please see a doctor for further evaluation and good luck. Read more...

Headache top right side back of head x4 days, constant, throbbing. Right eye bloodshot. No fever. Advil (ibuprofen) not helping. Should I go to ER or just wait?

Go to ER. Could be many severe things such as tumor, infection, aneurysm, cavernous sinus infection, intra-cranial bleed. You need seen now, and stop the advil (ibuprofen) it thins your blood and may make it worse or cause problems if you need surgery. Read more...
Hemicrania continua. If you've been examined and had imaging and everything is normal, one possibility is hemicrania continua, an interesting headache disorder with headache and red eye on one side of the head. It is very responsive to a medicine called indomethacin. Migraine of course is also a possibility. Hope this helps, I'd love to hear what happens next! Read more...