Under Perens' definition, open source describes a broad general type of software license that makes source code available to the general public with relaxed or non-existent copyright restrictions.
1 Illnesses such as the flu or colds. Home treatment of your flu and cold symptoms usually will relieve lightheadedness. 2  Vomiting, diarrhea, fevers, and other illnesses that cause dehydration.  Very deep or rapid breathing (hyperventilation).
Lightheadedness can be caused by orthostatic hypotension (a drop in blood pressure after you stand); hunger; common illnesses and infections, such as colds; hypoglycemia (low blood sugar); dehydration; heart problems; or feelings of anxiety and panic.