Apple seed contains a substance called amygdalin in plenty. Which is converted to cyanide as soon as you come in contact with your digestive system. This substance mainly consists of sugar and cyanide. Which later on converts into hydrogen cyanide as soon as it comes in contact with the digestive system. Which can cause your death.
Cyanide is primarily a poison. Which people also use in suicide. There are some other similar fruits. In whose seeds cyanide is found. These fruits are named apricots, cherries, plums, peaches and apples. The seeds of all these fruits can prove to be fatal for you.
If you have consumed the seeds of these fruits and are having problems like headache, vomiting, stomach cramps, go to the doctor immediately. If you eat more than 0.5 to 3.5 milligrams of this, you can also die. So whenever consuming these fruits, remove the seeds with caution.