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).
High Blood Pressure. Hypertension, also known as high blood pressure, can cause lightheadedness. Other symptoms of high blood pressure include confusion, chest pain, irregular heartbeat and nosebleeds. Feeling lightheaded may be an indication of a serious complication.