SOME INFORMATIONS ABOUT COUGH ; ( Source;- webmd )

  When Is a Cough Just a Cough?

Almost never, actually. If you have a cough, especially if you’ve had it for several weeks or more, there’s probably a reason worth checking out. It could be brought on by a cold, allergy, digestive issue, or even disease. Most of the time, it’s nothing serious, but some signs can tell you when you should be more concerned.

Things in the Air

Air that’s polluted with chemicals like sulfur dioxide or nitric oxide can trigger a cough. Mold and dust can do the same. Using special filters on your air-conditioning unit or wearing a mask on your face when you go outdoors may help.

Common Cold

It’s caused by a virus that gets in through your mouth, eyes, or nose from tiny droplets in the air. You can catch it from a sick person’s cough or sneeze, or through touch -- if you grab a doorknob with the virus on it, for example. In addition to the runny nose and sneezing fits it brings on, a cold also can get in your airway and make you cough. It usually runs its course in a week or so -- see your doctor if it’s severe or lasts 2 weeks or more.

Flu

Like a cold, the flu virus infects your throat, nose, and lungs. You get it when sick people sneeze or cough into the air around you or you touch something they touched. Generally, the flu makes you feel worse than a cold. It’s more likely to give you a high fever and chills, and less likely to cause sneezing and a runny nose.

When Is a Cough Just a Cough?

Almost never, actually. If you have a cough, especially if you’ve had it for several weeks or more, there’s probably a reason worth checking out. It could be brought on by a cold, allergy, digestive issue, or even disease. Most of the time, it’s nothing serious, but some signs can tell you when you should be more concerned.

Things in the Air

Air that’s polluted with chemicals like sulfur dioxide or nitric oxide can trigger a cough. Mold and dust can do the same. Using special filters on your air-conditioning unit or wearing a mask on your face when you go outdoors may help.

Common Cold

It’s caused by a virus that gets in through your mouth, eyes, or nose from tiny droplets in the air. You can catch it from a sick person’s cough or sneeze, or through touch -- if you grab a doorknob with the virus on it, for example. In addition to the runny nose and sneezing fits it brings on, a cold also can get in your airway and make you cough. It usually runs its course in a week or so -- see your doctor if it’s severe or lasts 2 weeks or more.

Postnasal Drip

When your body makes too much mucus, it drips down the back of your throat and can trigger coughs. Lots of things can cause it, including infections or allergies. Your treatment will depend on what that is. For example, if you have an infection, your doctor may give you antibiotics. Allergies can be managed with lifestyle changes, medication, or allergy shots.

Asthma

This happens when your airways narrow and swell. It can make it hard to breathe, and you may cough up mucus. Things that can trigger an asthma flare include pollen, dust, smoke, exercise, cold air, the common cold, and even stress. Your doctor can help you recognize and avoid triggers. She also may give you medication to help prevent an asthma attack and a drug you inhale in case one comes on sAcute Bronchitis

 An infection of your throat-nose-lung area makes your bronchial tubes -- which carry air to and from your lungs -- inflamed. It usually gets better within a few days, but you may have a cough that brings up a thick, colored mucus for a couple of weeks. If that doesn't go away or keeps coming back, you may have another problem, such as chronic bronchitis -- a type of COPD. See your doctor to get the right treatment.

. Gastroesophageal Reflux Disease (GERD)

This happens when stomach acid, sometimes mixed with partly digested food, flows back up toward your throat. That can irritate the tube that connects your throat to your stomach and make it hard to swallow. It also can bring on a dry cough. You usually can manage it with lifestyle changes and over-the-counter medications, but if you have a severe case, you may need prescription drugs or surgery. 

Pneumonia

When bacteria or a virus or fungus infects your lungs, they make the air sacs inside fill with fluid or pus. That causes a cough with thick mucus. You’re also likely to have fever, chills, and trouble breathing. Treatments may include antibiotics (if it’s caused by bacteria), cough medicine, and drugs that help with fever and pain

Chronic Obstructive Pulmonary Disease (COPD)

This is the name for a group of conditions, including emphysema and chronic bronchitis, that cause breathing problems. The tiny air sacs in your lungs get damaged or irritated, and that makes it hard for air to flow through. Treatment depends on the cause, but your doctor may give you medication and recommend lifestyle changes, like not smoking.

Whooping Cough

The medical name for this condition is pertussis. It’s caused by a bacterial infection, and it comes with a telltale deep, hacking cough. It gets its name from the “whoop” sound you make when you try to take a deep breath between coughing fits. Most of us have had shots to prevent it, but you need boosters as you get older. If you spend time with a baby, make sure you’re up to date with the vaccination. Doctors treat it with antibiotics, but whooping cough can be very dangerous for infants and the elderly.

Obstructive Sleep Apnea

Snoring is the most common symptom of this condition, but research suggests it also may make you cough when you’re awake. It happens when your throat muscles relax during sleep, and your airway closes, making it hard to breathe. Your doctor may recommend a machine called a CPAP (continuous positive airway pressure) that helps keep your airway open when you sleep, but some people need surgery.

Medication

ACE inhibitors -- drugs used to treat high blood pressure -- usually work well with few side effects. But up to 1 in 5 people who take them get a cough. If that happens to you, talk to your doctor. He may suggest you switch to a different drug.

Heart Failure

This is when narrowed arteries, high blood pressure, or another condition keeps your heart from pumping as strongly as it should. One symptom is a cough that brings up a white or pink, foamy mucus. Medication and lifestyle changes -- like exercise, improved diet, or weight loss -- can help.

Lung Cancer

A cough -- especially one that brings up blood -- can be a sign of lung cancer. But noticeable changes in a long-term cough -- or “smoker’s cough” -- also can be a sign, along with chest pain, headache, wheezing, and trouble breathing. Treatments for lung cancer may include radiation, chemotherapy, and surgery