Depression increases your risk of a number of diseases and other conditions by, for example, increasing levels of stress hormones such as cortisol or adrenaline. Depression can affect the immune system, making it harder for your body to fight infection. Vaccinations are even less effective in people with depression.
The total surface area of the Earth is about 7008510000000000000â 510 million km2 (197 million sq mi). Of this, 70.8%, or 7008361130000000000â 361.13 million km2 (139.43 million sq mi), is below sea level and covered by ocean water.
According to the CIA World Factbook, the total area of the United States is 9,826,675 sq km (3,794,101 square miles), 664,709 sq km (181,273 square miles) of which is water and 9,161,923 sq km (3,537,438 square miles) of which is land. 592,824 square miles of area is non contiguous.