DIABETES is a disease in which there is too much sugar in someone's blood.

THROW UP (informal) (=VOMIT): when food comes back from your stomach and out of your mouth.
DECAY: to become bad or rotten.

CONVINCE: to make someone believe something.

To fight LIKE HELL is to fight very hard.

To LET GO is to stop holding something/to leave.

INSULIN controls how much sugar is in someone's blood
An INJECTION is a way of using a special needle to give somebody a drug.

DAMAGE: to harm something; to make it not work properly.
TREATMENT: a way of trying to make a sick person better.
TUBE: A small, thin pipe.

WORK UP TO SOMETHING: (informal) to prepare for something gradually (little by little).

FUNERAL SERVICE: a ceremony that is held soon after someone dies. The body is usually buried in the ground or cremated.
To CREMATE someone: to burn their body after they are dead.