Lung grunges.

If you get lung grunges every year you need to strengthen your lungs.

And your immune system, of course.

If you get upper respiratory tract infections more often than once every two years (or so) you have weak lungs.

Strengthen them by drinking 2-3 cups of thyme (Thymus vulgaris) or sage tea every day for 1-2 months, every year.

Sage tea, made from Salvia officinalis, tastes disgusting (and if you still like it, you certainly will agree with my assessment, once you've drunk the tea every day for 2 months).
It's a good thing, then, that you can use other scented anti-inflammatory sages in addition to the less than tasty one. For instance, whitesage (Salvia apiana), or that most nicely scented of them all, Salvia greggii.

And help your immune system: sleep well, do your vitamins, exercise, try to lessen your stress factors, and eat well. Proteins are important to your immune system, so eat enough of those. Herbs, well, garlic and echinacea, ginger and yarrow, and all the other immune strengthening herbs you've heard of; do those you like. The herbs are the icing on the cake of your lifestyle.

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Related entry: Sage types