Haemorrhage This means bleeding. Most haemorrhages following dental extractions can be controlled with direct pressure.

Haemostasis This is when haemorrhaging stops.

Halitosis This is the medical term for bad breath. There are many causes from decaying teeth to infections of the throat or tongue. In most cases it is due to strong  flavoured food or smoking. Brushing the tongue with your toothbrush may help, and there are many mouthrinses on the market which claim to reduce the severity. Ask your dentist to look for any potential causes if this condition affects you.

Herpes labialis - see cold sores.

High volume aspirator Used by the dental nurse to aspirate (suck up) water and debris during drilling. see aspirator

Hypnosis / Hypnotherapy see What Helps.

Hypodontia Means having fewer teeth than normal. This affects about 6% of the population and may cause spacing.