Gum disease can be caused by a number of factors, but poor oral hygiene is the most common cause.

Poor oral hygiene, such as not brushing your teeth properly or regularly, can cause plaque to build up on your teeth.

Plaque

Your mouth is full of bacteria that combine with small food particles and saliva to form a sticky film known as plaque, which builds up on your teeth.

When you consume food and drink high in carbohydrates (sugary or starchy foods), bacteria in plaque turn carbohydrates into the energy they need, producing acid at the same time.

Over time, acid in plaque begins to break down your tooth's surface and causes tooth decay.

Bacteria in plaque can also irritate your gums, making them inflamed and sore.

Plaque is usually easy to remove by brushing and flossing your teeth, but it can harden and form a substance called tartar if it is not removed. Tartar sticks much more firmly to teeth than plaque and can usually only be removed by a dentist or dental hygienist.

Who is most at risk?

As well as poor oral hygiene, a number of things can increase your risk of developing problems with your gums. These include:

• smoking
• your age – gum disease becomes more common as you get older
• a family history of gum disease
• diabetes – a lifelong condition that causes a person's blood sugar levels to become too high
• a weakened immune system – for example, because of conditions such as HIV and AIDS or certain treatments, such as chemotherapy (powerful cancer-killing medication)
• malnutrition – a condition that occurs when a person's diet does not contain the right amount of nutrients
• stress