Many people claim to feel better after a good cry.

Whether it's to mourn the end of a close relationship or because of the sheer frustration of a bad day at work, once you come to wipe the tears away, the world can seem like it's been put back together again.

Now research has suggested that tears could actually be a way of flushing negative chemicals out of the body and doing you a world of good. We look at why it's good to cry.

Three types of tears

Emotional/stress-related tears

A study by Dr William H. Frey II, a biochemist at the St Paul-Ramsey Medical Centre in Minnesota, found that there is an important chemical difference between emotional or stress-related tears and those simply caused by physical irritants – such as when cutting onions.

They found that emotional tears contained more of the protein-based hormones prolactin, adrenocorticotropic hormone, and leucine enkephalin (a natural painkiller), all of which are produced by our body when under stress.

Basal tears

We all need the layer of protective fluid covering our eyeballs known as continuous or basal tears.

This fluid is secreted by the lachrymal glands, which sit above each eye, and without it our eyes would be in danger of drying out and become susceptible to bacterial attack.

Basal tears contain lysozyme, a powerful and fast acting antibacterial and anti-viral agent. Without this, the eye – because it's a moist environment – would suffer enormous amounts of bacterial attack and you could potentially go blind.

Eye watering

One of the most important functions crying can have is to protect our eyes from irritants and foreign bodies, such as dust or getting rid of the acidic fumes when cutting onions.

These tears are known as reflex tears. When our eyes come under attack from irritants, the lachrymal glands in our eyes start stimulating more fluid to wash away the irritant and drain it from the eye.

So, how do tears help us emotionally?

Emotional or stress-related tears are thought to help us through difficult times in a number of ways.

Physically, they are thought to wash toxic chemicals out of our bodies, while psychologically giving your feelings a good airing is thought to be a healthy tonic.

Stress release

Crying is thought to help reduce stress, which can have a damaging effect on our health and has been linked to a number of health problems including heart disease, high blood pressure, type-2 diabetes and obesity.

According to the Minnesota study, crying can help to wash chemicals linked to stress out of our body, one of the reasons we feel much better after a good cry. Higher levels of adrenocorticotrophic (ACTH) have been found in emotional tears (compared to reflex tears).

Removing this chemical from the body is beneficial because it triggers cortisol, the stress hormone – too much of which can lead to health problems associated with stress.

'Crying can help release tension and stress, as well as expressing emotions,' says Dr Abigael San, chartered clinical psychologist.

'When you're upset and stressed, you have an imbalance and build up of chemicals in the body and crying helps to reduce that.'

Dealing with sorrow

Aside from removing toxic substances from our body, crying can also have the psychological benefit of lifting our mood and helping us to deal with painful situations.

Deep crying is generally felt to be good for you in that it exposes and expresses deep emotions, which means they can then be dealt with.

'The Freudian theory is that it's beneficial to get feelings out, that if you let them fester they can affect you physically and psychologically,' says Professor Gail Kinman, an occupational health psychologist who has carried out research on crying in the workplace.

'Whether crying is good for you depends a lot on the reasons for it, the context, and how it is handled.

'Public displays tend to be looked down on, and any emotional catharsis in a situation, such as the work place, may be far outweighed by disapproval, embarrassment and guilt.

'Many women from my research, however, do say they sometimes feel like they need a good cry – and that they feel emotionally cleansed afterwards.'

Crying can also signal a need for help from others and bring people together.

People are usually more likely to help someone when they see them dissolve into tears, and it can prompt helpful behaviour.

It may also be a signal for physical contact, such as a hug or reassuring hand placed on an arm - and touch has been linked with helping stress reduction.

A group approach can help individuals in overcoming upsetting or difficult situations.

Too many tears

However, frequent crying is not always good for you and can be a sign of more serious conditions, such as depression, post-traumatic stress disorder and postnatal depression.

What's more, the healing affect of crying won't work for everyone.

Researchers have discovered that people who suffer a mood disorder are less likely to feel better after crying.

'If you're depressed and crying all the time, it's not good and you might need help,' says Dr Abigael San.

Counting the tears

88.8 per cent of people feel better after crying, with 8.4 per cent feeling worse.

On average women cry 47 times a year and men a mere seven.

Until puberty, crying levels are much the same for each gender – testosterone may reduce crying in boys while oestrogen and prolactin increases the tendency in girls.

Men may excrete more of the toxins related to emotional stress in their sweat because they have higher sweat levels than women.

The mantra to children 'Be brave, don't cry' might not be the most helpful because some believe crying can actually help reduce pain.

Other people also read:

Recession depression: why the link?

Time to talk about it: opening up on mental health.

Stress: what are the causes.

Last updated 16.08.2011

Natasha Mann Health journalist

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