Usually it's AIDS

Many causes of headaches

I would recommend prompt medical review

Tension, in my case.

Stress probably. Could have slept wrong and have tension in your neck. I've been having headaches and shoulder pain from my neck being all kinked up

Well, if you have serious concerns, it is always wise to consult your doctor rather than as for an online diagnosis.

That happens to me when if I'm stressed, or I haven't been drinking much water lately.

You married and living together?

Not drinking enough water 💦

Stress.. in my case

sinuses, perhaps?

brain leakage

Your JOB

Could be elevated blood pressure, or if it's cold it could just be constricting blood vessels.

Flu, viral illness or stress.

Dehydration? Drink water

A back slap.