I took my daughter to get a sports physical today. The physician noticed a swollen lymph node on her neck.?

Most are fine. Lymph nodes are small organs (many people describe them as swollen "glands"). They work by giving a convenient place for the immune system to interact with invaders such as viruses and bacteria in order to fight them. I think of them as the local "battlefields" of the immune system and the nodes closest to the area swell. Have her see her doctor to make sure it is going away, but it is likely ok.
Usually is benign. Lymph nodes are located throughout the body & generally noticeable in exposed areas like the neck. They are usually pea sized at rest and enlarged when stimulated by bug bites, dermatitis, drainage or infection. They rarely can become damaged by infection & grow to golf ball size & need drainage or removal. Most enlarge and later shrink back down within a 3 wk cycle unless chronically s.
Lymph nodes. Swollen lymph nodes is common in children and could be benign condition. There are certain area where lymph nodes require medical attention, like supra clavicular, spleen or liver enlargement. But lymph node enlargement in the neck, unless it feels hard and attached to underlying structure should not be worrisome.

Related Questions

What do I do now? I have had a swollen lymph node in my neck for about 6 weeks now. Sometimes it is easily felt but other times it is not so pronounced, but is always larger than the right side. I recently went to the doctor due to this and pain in my sp

You. You should have a ct scan of your abdomen and pelvis to get a good look at the liver and spleen. Also make sure you get a cbc, if your white count is elevated then the lymph node should be investigated. Lastly, since you are a smoker and have had such a significant weight loss, a cxr is also a good idea. Best of luck.
See a doctor. Go to a local medical clinic and have the doctor evaluate the nodes, better safe than sorry.
Monitoring Centers. Lymphatic system absorbs/carries things too big to go into the arteries/veins like bacteria eaten by white cells and digested food. Lymph nodes "taste" the lymph for anything bad like bacteria/viruses/cancers, etc. When it detects a problem, it alerts the immune system and your body reacts. They enlarge in response to the inflammation they create when they react. They shrink when all is well.

I have had this lump in my neck all my life that fits the description of a swollen lymph node. The doctor says its harmless but swollen lymph nodes are only suppose to last like a few weeks and I've always had it. What should ido?

Some. Some lymph nodes are bigger than others, and if this has truly been stable throughout your life, then it's not something to worry about. Lumps in the neck aren't always lymph nodes. There can also be congenital cysts of various type that look and feel like a node but are actually just contained fluid. Again, the long-term stability of this in your case would argue pretty strongly against it being anything bad.
Not a lymph node. Lymph nodes swell when there is infection present somewhere in the vicinity. After the infection is cleared they will return to their normal size.
LN can stay big. Sometimes after a lymph node has enlarged due to an infection, it doesn't return to its previous size. I have two that got big when I had pneumonia over 20 years ago that I can still feel. I'd be more concerned if they were new and getting bigger, but if you've had them for years and they're the same size, they're probably nothing. If you're still worried, tell your doc.