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.
When observing landmass, for instance, Russia is the largest country in the world at 6,592,771 square miles with Canada's 3,854,082 square miles placing it well behind Russia in second, and the United States at just under that with 3,717,727 square miles of landmass to its name.