How to tell the difference between the common cold and the flu.💫💫💫

Winter is flu season. During this season, many patients with cold symptoms think they have the flu. Patients diagnosed with the common cold after examination may even worry that the examination was not careful enough. They will question the doctor's examination. So what is the difference between the common cold and the flu?

Etiological differences.

Common cold:

The common cold can be caused by different pathogens. They include
coronavirus, respiratory syncytial virus, ECHO virus, adenovirus, rhinovirus, influenza virus, and parainfluenza virus, among others. Common colds in children are caused by respiratory syncytial virus and parainfluenza. Adult colds are mainly caused by rhinoviruses.

Flu: 

Influenza is caused by the influenza virus. It is a single-stranded, negative-stranded, segmented RNA virus. It belongs to the Orthomyxoviridae family. Influenza viruses are classified into four types: A, B, C, and D according to their matrix proteins and nucleoproteins. The main causes of influenza in humans are types A and B. There are many glycoprotein protrusions such as hemagglutinin (H) and neuraminidase (N) on the outer membrane of the virus. Influenza A viruses are named according to the difference between these two glycoproteins, such as H1N1, H2N2, H5N1, etc. Influenza B is divided into two strains, Victoria and Yamagata. 

Epidemiology of the common cold and flu.

Common cold:

The common cold is less contagious and not classified as an infectious disease. It is mainly infected by inhaling infected droplets or touching infected secretions and then touching the nose. The population is generally susceptible. Severely ill patients are rare. It can happen all year round and has no apparent seasonality.

Flu:

Influenza is highly contagious and spreads quickly. Influenza viruses are mainly spread by droplets from sick and latently infected persons. It is also spread by aerosols in crowded and poorly ventilated spaces. The population is generally susceptible. The following groups of people are more likely to develop severe disease after infection:

1. Children under 5 years old. In addition, children younger than 2 years are more likely to develop serious complications.
2. Seniors 65 and older.
3. Patients with cardiovascular disease (except hypertension), chronic respiratory disease, liver disease, kidney disease, blood system disease, endocrine system disease, nervous system disease, immunosuppressed, cancer, etc.
4. Obesity: BMI>30.
5. Pregnancy and perinatal women.

Influenza mostly occurs in summer and winter. It is generally seasonal.

Clinical manifestations.

Common cold:

The common cold has a shorter incubation period and a more acute onset. Common symptoms are nasal congestion, sneezing, coughing, sore throat and chest discomfort. Fever, headache and other complications are rare. Symptoms of generalized pain and fatigue are mild. In the absence of complications, it usually takes 5 to 7 days to heal.

Flu:

The incubation period of influenza is generally 1 to 7 days, and most is 2 to 4 days. The patient's body temperature can reach 39 to 40 degrees. It can be accompanied by chills, marked headache, and generalized pain is common and severe. The flu is sometimes accompanied by nasal congestion, sneezing, sore throat, mild to moderate chest discomfort and coughing. The most common complication of influenza is pneumonia. Others include heart and nervous system damage, myositis, rhabdomyolysis, shock, etc. Laryngitis, otitis media, and bronchitis are more common in children with influenza than in adults. In uncomplicated patients, systemic symptoms generally improve 3 to 5 days after onset, but physical recovery and cough usually take longer. 

Treatment.

Common cold:

There are no effective antiviral drugs for the common cold. Generally, decongestants, antihistamines, expectorants, antitussives, antipyretic analgesics, etc. are used for symptomatic treatment. Isolation and hospitalization are generally not required.

Flu:

Common anti-influenza virus drugs for influenza include M2 ion channel blockers (such as Amantadine), neuraminidase inhibitors (such as Zanamivir, Oseltamivir), and hemagglutinin inhibitors (such as Arbidol). Fever patients can undergo physical cooling and take antipyretics. Sputum expectorants and antitussives may be prescribed for patients with severe sputum and cough. Symptomatic treatment according to the patient's condition. If the patient's symptoms are severe or the underlying disease is significantly aggravated, the patient needs to be hospitalized. Both clinically diagnosed and confirmed patients should be treated in isolation.

Prevention.

Good personal hygiene is an important measure to prevent all respiratory infections such as frequent hand washing, keeping the environment clean and well ventilated, wearing a mask, etc.

Common cold:

There is no need for drug prophylaxis and no specific vaccine for the common cold. The best way to prevent it is to practice good personal hygiene.

Flu:

The best way to prevent the flu is to get the flu shot. Key groups such as healthcare workers, patients with chronic diseases, pregnant women, the elderly over 60 years old, children 6 months to 5 years old, and those who need to take care of children less than 6 months old should be vaccinated annually. Post-exposure drug prophylaxis is available for close contacts who have not been vaccinated or have not yet acquired immunity after vaccination and who are at high risk for severe influenza. It recommends taking oseltamivir or zanamivir once daily for 7 days within 48 hours of exposure.