tiredness, change in environment, it could all be possible

Take some vitamins, make sure you eat properly, and start taking echinacia and goldenseal root. All of these should help support your immune system.

Get some cod liver oil capsiles, it helps to improve the immune system. More sleep would help, or less stress.

What are your symptoms, each time you become sick? be specific, please.

Smoking effects your absorbtion of vitamins and iron. This would weaken your immune system, if you smoke.

I can think of a few things. 1.Are you female? If so could you be pregnant? 2.Was your doctor thorough or did he/she just do a quick exam and then dismiss your problems as this or that? Have you thought about a second opinion? 3.When my daughter had strep throat she would get sick one day and then be fine for a whole week. This went on for about 4 weeks and I finally took her to the doctor. I had him test her for strep because a friend of mine's daughter went through the same thing and it came back as strep throat. I don't think the doctor believed me but he did the test anyway and guess what...the strep test came back positive. You are your first line of defense in the battle for your health. If a doctor says everything is fine but you still continue to feel ill get a second opinion. You never know when one doctor just might know something your other doctor doesn't. Be persistent and read as much as you can on your symptoms and their possible causes. If you truly think you see something and you can say "hey , that sounds like what I am experiencing" talk to your doctor about it. Don't let Him/Her dismiss your concerns. It could just save your life one day.

I have several theories on this, however very lengthy, here are the shorter versions. Do you try to live in a germ free world? This could cause your system to not be exposed to any germs and not build up immunities to any germs, therefore small germs make you sick. This could be caused by the medications that you take for your colds or just the antibacterial soaps and chemically enhanced cleaners that you use in your home. I read an article about household cleaners and "new moms" that constantly clean with these new chemicals in the kitchen and floor products... they are proving that more and more children are getting asthsma from these fumes and lingering chemical deposits that enter into their food and possibly entering into their skin when young children crawl or play on the floors. Scary stuff, to be TOO clean.. and make your kids sick.. or anyone sick for that matter.

If you are otherwise healthy, the biggest drawback to a healthy immune system is inflamation from oxidation. It is at the cellular level where this process begins. The remedy is taking high quality anti-oxidant supplements and eating food with a high anti-oxidant value.

I havent really read what other people said so im sorry if im repeating anyone. But anyways i know it probably sounds like something your mum would of said but to have a strong immune system you need to be eating the right foods, i always used to get sick in winter atleast twice with very high temprature and what not. But then one winter i started eating quiet alot of garlic, maybe one garlic peice thing on a peice of toast twice a week, and you know what it does wonders, or if you find garlic too much then onion would do. Also fruits like oranges that are high in Vitamin C would help out. And also frequent hand washing helps more then you would expect! Hope this helped.