Cold medicines are a group of medications taken individually or in combination as a treatment for the symptoms of the common cold and similar conditions of the upper respiratory tract. The term encompasses a broad array of drugs, including analgesics, antihistamines and decongestants, among many others. It also includes drugs which are marketed as cough suppressants or antitussives, but their effectiveness in reducing cough symptoms is unclear or minimal.While they have been used by 10% of American children in any given week, they are not recommended in Canada or the United States in children six years or younger because of lack of evidence showing effect and concerns of harm. One version with codeine, guaifenesin, and pseudoephedrine was the 213th most commonly prescribed medication in 2017, in the United States, with more than two million prescriptions. Types
There are a number of different cough and cold medications, which may be used for various coughing symptoms. The commercially available products may include various combinations of any one or more of the following types of substances:
Mucokinetics, or mucolytics, are a class of drugs which aid in the clearance of mucus from the airways, lungs, bronchi, and trachea. Examples are carbocisteine, ambroxol, and bromhexine. Expectorants are substances claimed to make coughing easier while enhancing the production of mucus and phlegm. Two examples are acetylcysteine and guaifenesin. Antitussives, or cough suppressants, are substances which suppress the coughing itself. Examples are codeine, pholcodine, dextromethorphan, noscapine, and butamirate.
Hyperpnea, on the other hand, is defined as breathing an increased volume of air, with or without an increase in respiration rate.Others give another classification: tachypnea is as any rapid breathing, hyperventilation is increased rate of breathing at rest, hyperpnea is an increase in breathing that is appropriately proportional to an increase in metabolic rate.A third paradigm is: tachypnea is abnormally rapid and shallow respiration (though some may argue this is inaccurate as breathing differs from respiration), hyperventilation is increased rate or depth of respiration to abnormal levels causing decreased levels of blood carbon dioxide and hyperpnea is any increase in breathing rate or depth that is not normal. Threshold definition
As normal respiratory rate varies with age, the definition of tachypnea also varies with age. Causes
Tachypnea may have physiological or pathological causes. Both of these categories would include large lists of individual causes. Physiological causes
Physiological causes of tachypnea include exercise. This type is usually not a cause of concern unless its excessive. Pathological causes
Pathological causes of tachypnea include sepsis, compensation for diabetic ketoacidosis or other metabolic acidosis, pneumonia, pleural effusion, carbon monoxide poisoning, pulmonary embolism, asthma, COPD, laryngospasm, allergic reaction causing airway edema, foreign body aspiration, tracheobronchomalacia, congestive heart failure, anxiety states, haemorrhage, or many other medical issues. Etymology and pronunciation
The word tachypnea () uses combining forms of tachy- + -pnea, yielding "fast breathing". See pronunciation information at dyspnea. See also
Control of respiration
Hypoventilation
List of terms of lung size and activity
Bradypnea

References
External links
 The dictionary definition of tachypnea at Wiktionary