The diseases in this category are the result of disorders of the endocrine system. This system releases hormones into the blood from the endocrine glands and tissues. Hormones are molecules that send signals from one type of cell to another. There are hundreds of different types of endocrine disorders.

See also Map 85 Diabetes mellitus.

Clusters of high SMRs are found in and around Birmingham and in the south Wales valleys. Scotland also has high rates. Low rates are found in more affluent areas where wealthier older people retire.

This cause of death is more common for females than for males, with 62% of all deaths from these causes being of females. As the age–sex bar chart shows, it is women over the age of 60 who are most likely to die from these causes.

Nearly a quarter of deaths in this grouping are due to thyroid problems. Just over a tenth (11.2% for ICD-10) of the deaths in this category are due to morbid obesity. Also included here is cystic fibrosis, which is a hereditary disease causing progressive disability affecting the lungs and digestive system. Morbid obesity is defined as a body mass index of more than 35kg/m2. A BMI of between 25–35 carries increased mortality risk but would not be recorded as cause of death. When noted as a cause of death, the BMI is likely to be well over 35.