Is It a Cold, Influenza, or Pneumonia?

W. Steven Pray, PhD, DPh; Joshua J. Pray


US Pharmacist. 2004;29(1) 

In This Article


The Common Cold

The symptoms of the common cold depend on its viral cause. However, certain generalizations can be made. Symptoms usually begin one to two days after viral contact and are usually mild. Most episodes begin with a scratchy, tickling, or soreness of the throat. Throat discomfort progresses until it becomes moderately painful but usually resolves by the second or third day. Nasal involvement usually begins as the sore throat improves. Initially, the person notices a copious, thin discharge that persists for about two days. After this time, the consistency changes—it thickens and becomes purulent. Typically, the nose is partially or totally blocked most of the time. The purulent discharge and nasal blockage gradually improve by the fourth or fifth day. Cough begins at about this time and may be productive initially, gradually becoming tight, dry, and nonproductive. The cold can produce other symptoms that depend on the specific causative virus, including fever, lacrimation, sneezing, malaise, and headache. The onset and progression of symptoms with the common cold is gradual, and those infected appear well to others. Most cold sufferers can function without any interruption in work or school.


Like the common cold, the symptoms of influenza vary among people. Each year, the flu subtype that sweeps the United States may produce symptoms that differ somewhat from those seen the previous year.[11,12] However, some generalizations are useful with influenza. For instance, the onset of flu is abrupt (unlike that for the common cold). One can feel well in the morning but extremely ill in the afternoon. When symptoms begin, the person may notice some overlap with common cold symptoms. Sore throat and watery nasal discharge occur in both conditions. However, the discharge associated with the flu does not usually become thick and purulent as it does with the common cold. Although headache and fever occur occasionally with the common cold, they are more common and more severe with influenza. The fever of influenza may be as high as 106°F, which exceeds that seen with the common cold. The person with influenza may appear ill to others, with flushed, warm skin and watery, reddened eyes, but the common cold does not typically produce dermatological or ophthalmic symptoms. Perhaps the greatest difference between the two illnesses is the degree of malaise and discomfort. Influenza causes malaise that results in the patient wishing to simply sleep or rest to recover from its effects. The person also experiences severe aches and pains in the muscles, joints, and periophthalmic areas. This discomfort contributes to the desire to rest and be left alone. Thus, it is far more common for influenza patients to voluntarily miss school or work.


Pneumonia mimics the cold and flu. Manifestations can vary, as with the other illnesses, depending on its causative organism. Thus, the pharmacist should refer a patient with suspected pneumonia to a physician for a chest film.

With pneumonia, the person typically notices that breathing has become labored, manifested by dyspnea and tachypnea. The person may notice that his or her upper trunk is being pushed back and forth with the effort of inspiration and expiration. Bacterial pneumonia may be accompanied by shaking chills, high fever, sweating, chest pain (pleurisy), and a productive cough with yellow/green mucus. Viral pneumonia causes muscle pain, fatigue, fever, headache, and a nonproductive cough. "Walking pneumonia," usually due to Mycoplasma, produces milder symptoms. Although pneumonia also causes various lung sounds, (eg, rhonchi and rales), the typical community pharmacy does not have the equipment or space for this type of assessment.


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