My nephew is just 27 years old and yet his blood pressure shoot to as high as 190/130?

This is really early to have High BP. The High BP is of two types 1 Primary - which is usually with advance age due to arteriosclerosis.
Secondary - when high bp is seconadary to a primary cause like
Renal disease - eg renal artery stenosis ( usually in young adults ) Ch.Renal condition starting with acl.glomerulonephritis
Due to endocrinal diseases like increased secretion of aldosterone or some tumor in supra renal.
coartcation of aorta where aorta is narrowed after its origin .
Sec to certain drugs Most likely ur nephew falls in High BP due to some tretable secondary cause. Have investigations on that line.

It's not good as far as his mortality is concerned. He should be checked for Portal Hypertension or any urological problem specially kidney.
A trip to the doctors methinks before he explodes!!
He is known as young hypertensive. Seeing a doctor is urgent. Must do some blood and urine investigation to rule out conditions that are treatable. A tumor of adrenal glands (known as pheochromocytoma) may secrete hormones that cause high blood pressure. Treatment includes control of blood pressure with medications first followed by operation.
Call the doctor. There can be many reasons for such a high pressure and only a physical exam can tell you the correct one and how to treat it.
tell him to do RAMDEV'S exercise if u r n indian then of whom i m talking otherwise concern any 1 who is living in india
care her. avoid salt and meats