|
|
Only one in 10 cancer deaths is caused by the primary tumor. The vast majority of cancer mortality is caused by cells breaking away from the main tumor and metastasizing to other parts of the body, such as the brain, bones, or liver.
Congestive heart failure is a serious disorder that carries a reduced life expectancy. Heart failure is usually a chronic illness, and it may worsen with infection or other physical stressors.
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
Approximately one in three babies in the United States is now delivered by cesarean section. The number of cesarean sections in the United States has risen 46% since 1996.
A strange skin disease referred to as Morgellons has occurred in the southern United States and in California. Symptoms include slowly healing sores, joint pain, persistent fatigue, and a sensation of things crawling through the skin. Another symptom is strange-looking, threadlike extrusions coming out of the skin.
![Several species of squirrels have melanistic phases. In large parts of United States and Canada, the](https://biology-forums.com/gallery/47/medium_12359_08_06_12_5_35_15.jpeg)
![The monthly changes of angle between the direction of illumination by the Sun and viewing from Earth](https://biology-forums.com/gallery/47/medium_12359_23_01_13_7_07_24.jpeg)