COUGHS often seem to hang around FOREVER, and this year's flu season has been a prime culprit.
Allergies certainly can cause coughs as well, but typically allergy coughs are more the dry, annoying, clear-your-throat variety, rather than the wet sounding coughing fits (that worsen every evening and prevent sleep) which come from viral respiratory infections. Typically there are a few days of headaches, fever, body aches, sore throats and stuffy nose, but then the cough itself may persist for up to SIX WEEKS after the initial illness.
Is there anything that can be done for a cough that wont go away? Yes, absolutely.
Will an antibiotic fix a cough? Especially is there is green mucus? Probably NOT, because the vast majority of respiratory infections are viral. Green mucus does not equal bacterial infection.
So you NEVER need an antibiotic for a cough? No, that is not true- sometimes a cough IS being caused by a bacterial infection (possibly a pneumonia), but this is the exception, not the rule. If you are a week into your symptoms, slowly getting better, and then suddenly you feel a ton worse and develop a fever, this might be a bacterial infection setting up shop AFTER the virus cleared the way past your body's defenses. For this scenario, yes, you need an antibiotic.
If antibiotics don't help, why see your doctor for a cough?
Certainly not every cough NEEDS to be evaluated by a physician. Over-the-counter cough products include DM (dextromethorphan) (which works at the brain level, decreasing the drive to cough) plus expectorants like guaifenisen (ex. trade name Mucinex) to thin up the mucus. Combinations of these ingredients (along with decongestants to help stuffy noses) make up the cough/cold/flu products like Dayquil/Nyquil/Robitussin/etc. and may be helpful in alleviating cough and cold symptoms in adults.
Cool mist humidifiers next to the bed often bring relief, and honey (either taken as a straight teaspoon or in a hot tea) has been objectively shown to help improve coughs (though never for children younger than one year).
However, often after a viral respiratory infection, the lungs' defenses become overly reactive, creating too much mucus and then subsequent spasm of the airways- we call this "reactive airway disease" and this is the same process we see with asthma. Subsequently, persistent coughs often resolve more quickly when treated with prescription asthma inhalers or other oral medications (possibly anti-inflammatory steroids).
Additionally, there are other prescription cough medications that might help.
Benzonatate (trade name Tessalon) is a non-addictive, non-sedating medication that works in the lungs to decrease the cough reflex by numbing the stretch receptors in the respiratory tract. (In my clinical experience, this drug either works like a dream or has little impact, but its low side effect profile makes it an attractive choice.)
Finally, a cough that is keeping you (and/or your bed partner) up all night despite OTC medications may require a sedating prescription cough syrup. With our current opioid crisis, know that conscientious physicians are appropriately limiting the quantities of these potentially addictive medications, and this is not a long term solution.
Finally, a cough may come from other sources, such as acid reflux or sinus drainage or a medication side effect (such as from one class of blood pressure medications), which require different treatments.
BOTTOM LINE: See your doctor to evaluate coughs that get worse after a respiratory illness, or that wont go away- please don't expect antibiotics, but know there are other treatment options.