Headaches on one side only, dizzy, nauseus, hair falling out. Could this be a tumor or anyerism?

See your doctor. Headaches with dizziness and nausea should be evaluated by a doctor. A tumor can present like this, but so can migraines, metabolic conditions, infection, and a multitude of other possibilities. Aneurysms generally have no symptoms until they rupture. See your doctor!
Need Immed Eval. Although the symptoms could be of a garden variety headache, the dizziness is a little bit troubling to me. These symptoms could be common from a less common type of migraine that is associated with an impending stroke or other serious condition and should be checked out as soon as possible if these symptoms are new.
Need Immed Eval. Although the symptoms could be of a garden variety headache, the dizziness is a little bit troubling to me. These symptoms could be common from a less common type of migraine that is associated with an impending stroke or other serious condition and should be checked out as soon as possible if these symptoms are new.