What can cause low blood pressure?

Many things: If you have no symptoms then there is no worry. If you have symptoms you could be going into shock, adrenal insufficiency, dehydration, etc. See your internal medicine doctor.

Varies: Several possibilities, but here are some: dehydration, esp in the summer when we can loose more water than we realize. Medications (lots-best to talk with your doctor). Infections, mainly serious ones. Heart problems. Endocrine problems. Kidney problems. More. For some people a lower BP is normal.Because the list is long and complex, i'd encourage you to have a eval & discussion w/ your doctor.

Commonly dehydration: For the average person, the most common cause of low BP is from dehydration--not getting enough fluids/foods. For elderly this is even more common. Also, medications can also do this. Autonomic dysfunctions as in parkinson disease or advanced diabetes; heart failure, liver failure, rapid blood loss/bleeding etc...Are other major causes. If you have problem, consult doc. Good luck.

Many causes: Need full work up. Low BP can be autonomic nervous dysfunction such as vasodepressor syndrome, vasovagal, heart block, adrenal gland abnormalities, thyroid dysfunction, medications etc.

Low BP: Depends on the definition and setting of a given individual ;a large range of potential variables precludes a specific answer for your post.