It is difficult to tell without examining you what is causing your symptoms. An upper respiratory infection can cause lymph node swelling. If the lymph nodes in your neck are swollen, this could cause your neck to hurt. Being examined by your doctor again may help to clarify what is causing your symptoms, but here are some possibilities.
An upper respiratory infection can cause inflammation of the airways of the lungs. Usually when this occurs, you may cough when you are active or laugh. After the infection is gone, it is possible for the inflammation to linger. This inflammation can last for several weeks. Sometimes this inflammation may linger for 3 to 6 months. Eventually the inflammation will go away, and then the coughing will stop. This is called reactive airways disease (RAD) and behaves a lot like asthma. This inflammation often clears more quickly when it is treated with an inhaled steroid medicine that is used to treat asthma. Your doctor is the best judge of this.
Postnasal drip is drainage from the nose and sinuses dripping down the back of the throat. There could be several reasons for this drainage. One reason is an allergy. A second reason is a non-allergic, non-infectious inflammation in the sinuses that can linger after an upper respiratory infection. A third reason is chronic sinusitis. Postnasal drip can cause a sore throat and coughing as a result of irritation of the throat and lungs. You may experience the postnasal drip as a constant feeling of mucus at the back of your throat. Typically this is worse at night when you lay down to sleep. Generally this irritation feels the worst when you wake up and gets better as the day goes on.
The fat content in dairy products can thicken mucus. Generally eating dairy products with less fat content is helpful. Drinking plenty of water will help to thin the mucus so that it moves more easily. As long as you are not on a fluid restriction you should be drinking 6 to 8 8-ounce glasses of non-caffeine non-alcoholic fluid daily. Clearing your throat can irritate your throat and make it sore. When you feel the need to clear your throat sip some water to clear the mucus.
An antihistamine, like the Allegra® (fexofenadine), can dry up the postnasal drip. However, it may make the mucus thicker and more difficult to move. A decongestant like Sudafed® (pseudoephedrine) can thin the postnasal drip and decrease the swelling so it drains easier. A combination antihistamine-decongestant will do both. Check with your doctor to see if Allegra® (fexofenadine/pseudoephedrine), a combination antihistamine-decongestant, would help you more. Often an antihistamine and decongestant are taken only when the postnasal drip gets bad. It may be more helpful to take the antihistamine and decongestant on a regular basis.
A nasal wash helps remove mucus and germs from your nose and sinuses. This can temporarily decrease the postnasal drip and lessen coughing. A prescription nasal steroid spray decreases mucus production by decreasing the inflammation of the nose and sinuses. This may prevent the postnasal drip, sore throat, and coughing. To get the most help from a nasal steroid spray use it after doing a nasal wash. A nasal steroid spray does not provide immediate relief of symptoms. It may require several weeks of routine use to become effective. Sometimes it takes the antihistamine, the decongestant, and the nasal wash followed by the nasal steroid spray ALL used routinely to keep the postnasal drip from bothering you. Please read our Nasal Wash MedFact at http://www.nationaljewish.org/medfacts/nasal.html for more information about this technique. Share this information with your doctor to see if you would benefit from this daily treatment.