There are 125,000 new cases diagnosed each year
People with type 2 diabetes often live with a range of other problems, such as sexual dysfunction and anxiety about further complications, a poll shows.
A survey of 2,500 patients by Diabetes UK found nearly 25% had suffered sexual dysfunction and one in 10 had experienced eye damage.
Most participants also said they were concerned about the risk of further complications, such as heart attacks.
Diabetes UK said managing the condition properly could minimise problems.
Diabetes rates have soared in recent years with 125,000 new cases diagnosed each year, leaving 5% of the UK population with the most common type 2 version.
TYPE 2 DIABETES
Long-term condition caused by too much glucose in the blood
Occurs when not enough insulin is produced by the body for it to function properly, or when the body's cells do not react to insulin. This is called insulin resistance
Symptoms can be controlled by healthy eating, and monitoring blood glucose level
However, injections may eventually be required
One respondent said: "I haven't had any form of sex life with my husband for over two years, which coincides with my taking my meds.
"My doctor's response is that I obviously do not love my husband any more.
"I am so angry that female sexual dysfunction is not acknowledged and more help given."
Eight in 10 of those polled said they were worried about heart attacks, strokes and nerve damage.
Dr Marc Evans, a consultant diabetologist from Cardiff, said: "These results illustrate the everyday challenge facing those living with type 2 diabetes.
"If not managed correctly, this condition has wide-reaching, long-term implications."
Healthy eating and monitoring blood glucose levels are the most important ways of keep diabetes under control.
Caroline Butler, from Diabetes UK, added: "It's essential that everyone with diabetes works in partnership with their healthcare team to help manage their condition effectively."