Most people at some point in their childhood are infected with herpes zoster, caused by the varicella zoster virus, which at first causes a bout of chicken pox. The immune system learns how to defend against this illness, but shingles, although caused by the same virus, is sufficiently different to make the immune system unable to cure it instantaneously.
Once the chicken pox virus is defeated, the varicella zoster virus is eradicated from most parts of the body. However, the virus stays active in the ganglia next to the spinal cord, albeit suppressed by the immune system. However, sometimes, especially if the immune system is compromised for some reason or other, the virus can reactivate. This second activation is what is known as shingles. For many, the shingles infection is far more potent than the chicken pox one, and can lead to a lot more pain. Also possible is permanent nerve damage leading to problems such as postherpetic neuralgia.
Herpes zoster is not a contagious illness, however direct contact with a rash can give a person without resistance the varicella zoster virus. This is why it is a good idea to keep children well away from anyone with the virus, in case they get a bout of chicken pox as a result of exposure.
You can lower your chances of being caused shingles by the varicella zoster virus if you choose to take a vaccination against it. This vaccination will boost your immune system, decreasing your chances of contracting the disease by roughly half. Other ways to boost your chances of staying shingle-free are by having contact with children who have chicken pox (as this boosts your immune system), and also having a healthy and varied diet with plenty of fruit, vegetables and the necessary minerals the body needs.
The initial bout of chicken pox caused by the virus leads to a rash that is very dissimilar to the rash caused by shingles. The rash caused by shingles is usually focused on one area or side of the body, and can be a lot more painful. Also, although both rashes can look similar on the scale of individual blisters, the chicken pox rash can cause other people to get the virus. It is highly contagious, and as such it is a good idea to keep young babies and toddlers away from anyone with chicken pox. Contact with the rash is not necessary to be exposed to the virus, as the virus is also carried in coughs and sneezes of any affected person.
A lack of hygiene and cleanliness can lead to the spread of the varicella zoster virus. It is sensitive to heat and detergents, so if proper care is taken to clean hands, surfaces and body parts, the cause of shingles is stopped very effectively. However, since the virus is so contagious, especially from individuals who have chicken pox rather than shingles, catching the virus is often unavoidable. Most people will get chicken pox as a child, with shingles tending to affect older people more.