Sauna and health
In Finland, sauna is medicine, sauna is the poor man’s pharmacy - for hundreds of years the Finnish proverbs have revealed an ancient belief in the curing properties of sauna. There is also scientific proof that this is indeed the case.
Already as written in the Kalevala, the national epic of Finland, the old steadfast Väinämöinen warded off threatening diseases by warming up the sauna, casting the water on the stove and inviting the god of incantations to join him.
The earliest scientific research concerning sauna is from 1765, when a doctor, Anton R. Martin, from Stockholm researched saunas in Vyborg.
According to Dr Martin, the smoke in the saunas caused the eyelashes to grow inwards.
He also observed that a sauna:
- raises the skin temperature
- raises the pulse
- reduces the amount of urine
- relaxes painful muscles
All the last four points are reinforced by modern science.
Sauna’s relaxing properties
There are two scientific thoughts regarding sauna’s relaxing effect to human mechanism.
- Biochemical: sauna increases the production of endorphins in the brain, which result in a feeling of well being. (e.g. Hannuksela and Ellahham, 2001)
- Psychological: Psychoanalysts believe that sauna’s warm, peaceful atmosphere creates a kind of sense of returning to one’s childhood and even as far as into the mother’s womb, and thus results in a sense of well being.
Sauna and blood circulation
In a sauna, the most significant changes in the body occur in circulatory system. At room temperature only 10% of the blood circulation occurs in the skin. In hot temperatures the skin’s capillaries expand and in a sauna up to 70% of the blood will flow through the skin’s blood vessel systems. When the skin’s blood vessels expand, the heart will beat faster.
According to research, sauna does not play a role in deaths caused by heart attacks.
Sauna and ‘swimming in the hole in the ice’
When entering cold water directly from a hot sauna, the capillaries will contract and the blood pressure will rise sharply. A healthy person can easily endure this but for people with a heart condition this rise could be dangerous.
Sauna and alcohol
Intoxication will increase the risks to health because:
- the risk of slipping and falling will increase
- assessing the temperature level will become more difficult. Levels of arrhythmia will increase in excessive heat.
- falling asleep in the sauna can lead in dehydration
A warning: “Sauna should not be entered in the state of intoxication”, not from a moral point of view but there are clear medical reasons for the statement. (e.g. Roine and Seppä, 1992)
Sauna and pregnancy
In the 1970s, there were studies conducted into the effects of sauna on the foetal development during pregnancy. The research found no additional risks brought on by having a sauna. Virtually all the Finnish women have a sauna as normal during pregnancy.
Sauna - helping during illness
Sauna has been a subject of research as a treatment for various illnesses.
Flu
An Austrian research has found that sauna can reduce the symptoms of flu by 30%. This outcome has not, for the time being, been fully explained.
Asthma
Sauna heat can expand the bronchus, which can ease breathing. People with allergies to birch trees should avoid using a birch leaf whisk (vihta).
Rheumatism
Pain and aches can be alleviated for the duration of the sauna evening but the next day aches may increase.
Cardiac insufficiency (insufficientia cordis)
A Japanese study found that the cardiac blood flow eased, the heart’s pumping efficiency improved and the blood pressure went down. The heart size decreased. This improved the patient’s condition i.e. the heart was in a better condition.
Source: Professor Lasse Viinikka: The Heath Effects of Sauna (Saunan Terveysvaikutukset). Lecture, Saunaexpo 2009