What are symptoms of hypertension?

None: Usually none; that's why it's a silent killer. If it is very severe it sometimes causes a headache, vision and neurological changes.

Wide range: Usually there are no symptoms. Every person's body reacts to elevated blood pressure differently. You can feel generalized weakness and fatigue, dizziness or vague fuzzy-headedness, headache, blurry vision, and flushing. People commonly feel vague chest pressure or discomfort as well, which most often does not indicate any heart damage or dysfunction.

Usually none, but...: "silent killer" is a very fitting description, and this is why it is so important to treat high blood pressure even in the absence of symptoms. Severely high blood pressure (example 180/120) combined with headache, chest pain, or vision change is a medical emergency and deserves a call to 911 to avoid permanent damage or even death.