What serious health conditions make your gums/teeth bleed all of a sudden? i've never had this before??

A long list, but....: Anything that changes your resistance to infection. for instance inadequate diet short of some vitamins. An illness like the flu or something more serious can also do it. First try the obvious, do a good job with your home care and stay current with your dental appointments. See if that improves things.

Don't assume: Don't assume you have a serious health condition. You might just have gingivitis. Last professional cleaning? If more than six months, now is the time to call a local dentist for an appointment. Brushing and flossing alone may not be enough for your dentition.

Gingivitis: Bleeding gums can be a sign that you are at risk for, or already have, gum disease. Untreated gingivitis can advance to periodontitis and can eventually lead to the tooth loss and other health problems. See your dentist ASAP because the sooner you treat it the better the outcome.