My dad takin 11 medications for diabetes & high blood pressure . yesterday he felt lost of consciences and he was forgetful. possible overdose??

Overdose?: This is a possibility but not necessarily an intentional overdose. There is always a concern that his blood sugar became low or his blood pressure dropped. Loss of consciousness should be followed by a medical evaluation. It is imperative that his physicians who are prescribing his medicines to limit the chance of medication interactions.

Overdose : There may be several reasons for his reaction. Extremely high or low blood pressure or blood sugar, "mini stroke " or a reaction to his medication. In any case he needs to be checked out

Drug interactions: It probably is the result of interaction between those medicines; not taking too much of one/some. He needs a medication consult. Often all of a person's doctors are not aware of what others have prescribed. Your father's primary care doctor, possibly with assistance from a pharmacist, needs to review all medications checking for redundancies & interactions. Docs are gaining expertise in this

Assumptions make an: Yes you know the rest. Did truly loose consciousness? That is what's known as syncope, and there are multple possible explanations. Hypogycemia is only one. Cardiac problems, low blood pressure, seizure, transient ischemic attack, renal problems, drug reaction to name just a few. If you notice this happening dial 911 and let the paramedics come assess him. Otherwise call his doc for followup asap.