What are some causes for pressure like feeling in head that has occurred for 3-4 days on and off randomly?

Many possibilities! Causes for a pressure-like feeling in the head can be from a number of things, including a viral infection (cold, flu, etc.), sinus congestion (sinusitis, allergies, etc.), stress (tense muscles, tense neck, etc.), medications, other "drugs" (drug use, drug withdrawal, caffeine effects, etc.), hydration changes, blood sugar changes, fumes (carbon monoxide, etc.), rare tumors, rare aneurysms, etc..