Every year you should have a blood test to check your blood sugar control (Hba1c) kidney function and cholesterol. Your urine also needs to be checked yearly for evidence of protein leakage (which is a marker for kidney damage).
Every 6 months you should have your blood pressure checked, and once year you should have a more detailed check with the nurse, which will involve measuring your weight, checking your feet, nerves and circulation and gives you an opportunity to discuss your condition.
Once a year you should attend for eye screening; which involves looking at the back of your eye for signs of eye damage.
Please visit the NHS website to find out more about diabetes.