Underlying causes of low blood pressure. Low blood pressure can occur with: Prolonged bed rest. Pregnancy. During the first 24 weeks of pregnancy, itâs common for blood pressure to drop. Decreases in blood volume. A decrease in blood volume can also cause blood pressure to drop. A significant loss of blood from major trauma, dehydration or severe internal bleeding reduces blood volume, leading to a severe drop in blood pressure.
Influenza, commonly called the flu, is caused by viruses that infect the respiratory tract. Flu symptoms include fever, chills, cough, sore throat, headache, muscle aches, and. fatigue. The incubation period for flu is about one to four days. Flu is contagious, and symptoms may last up to seven to 14 days.
Flu viruses come in three basic types: A, B and C. They may also be classified into flu subtypes. Flu types A and B cause most cases of flu with the typical symptoms of aches, fatigue, coughs and fever. Type C usually causes less severe symptoms. Flu viruses are always evolving, and different types are more common at different times.