Your GP will be able to diagnosis acne by looking at your skin. This will involve examining your face, chest and back for the different types of spot, such as blackheads or sore, red nodules.

How many spots you have and how painful and inflamed they are will help determine how severe your acne is. This is important in planning your treatment.

Four grades can be used to measure the severity of acne:

• grade 1 (mild) – acne is mostly confined to whiteheads and blackheads, with just a few papules and pustules
• grade 2 (moderate) – there are multiple papules and pustules, which are mostly confined to the face
• grade 3 (moderately severe) – there is a large number of papules and pustules, as well as the occasional inflamed nodule, and the back and the chest are also affected by acne
• grade 4 (severe) – there is a large number of large, painful pustules and nodules

Acne in women

If acne suddenly starts in adult women, it can be a sign of a hormonal imbalance, especially if is accompanied by other symptoms such as excessive body hair (hirsutism) and irregular or light periods.

The most common cause of hormonal imbalances in women is polycystic ovary syndrome (PCOS). PCOS can be diagnosed using a combination of ultrasound scans and blood tests. Read more about diagnosing PCOS.