Blood pressure which is lower than the normal limits is far less common than a level higher than normal, and the long-term implications for health are far less serious. However, people whose blood pressure is consistently lower than normal may be prone to dizziness and fainting, as the supply of blood to the brain may be interrupted momentarily if the pressure falls below that necessary to maintain the flow to the head. They may also feel cold and tire easily.

The heart pumps a constant supply of blood around the body through arteries, veins and capillaries. Blood pressure is a measure of the force of the blood on the walls of the arteries as the blood flows through them. It's measured in millimetres of mercury (mmHg) and recorded as two measurements:

• systolic pressure – the pressure when your heart beats and squeezes blood into your arteries
• diastolic pressure – the pressure when your heart rests between beats

The essential oil of Rosemary has been used to raise blood pressure to a more normal level. It is tonic and stimulating and responds in many ways to the needs of people with low blood pressure. Other stimulant oils, such as Black Pepper and Peppermint are helpful, particularly if fainting is a frequent problem, but they should not be used to excess. Hyssop and Sage are other possibilities, but both present some risks of toxicity, so its use is not advised except by very experienced therapists.

Massage, perhaps of a brisker and more vigorous nature than we usually use in aromatherapy, is once again the best form of therapy, and combine this with regular exercise, gentle at first, as a means of improving the general efficiency of the circulatory system.