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Cold Vs Flu

Is it a cold or the flu?

With winter in full swing, it is important to know what steps to take to prevent winter health risks.

While Bay Area residents do not typically have to worry about slipping and falling on icy pavement or risking a heart attack from shoveling snow like others throughout the United States, there is a still a risk of catching a cold or seasonal influenza (flu).

The common cold and flu are both respiratory illnesses but they are caused by different viruses. Both colds and the flu are easily transmitted, passing from person to person through the air by coughing or sneezing and through contact between people.

While it is nearly impossible to avoid coming into contact with cold or flu viruses altogether, there are some simple steps to take to help maintain health:

  • Stay away from people who are sick
  • Wash hands for at least 40 seconds with warm water and soap often
  • Sneeze or cough into the crook of your arm
  • Avoid touching the eyes, nose and mouth
  • Get plenty of sleep
  • Keep physically active and exercise regularly
  • Stay hydrated and drink plenty of water
  • Dress appropriately for the cold weather

Because colds and the flu have similar symptoms, it can be difficult to tell the difference between them based on symptoms alone. In general, the flu is worse than the common cold, and symptoms are more intense. People can develop very serious complications associated to the flu.



Colds are very common and are the leading cause of missed days from school and work. The average adult experiences two to three colds each year and children have more according to the Centers for Disease Control and Prevention (CDC). Colds are usually not serious. While cold symptoms are the number one reason for doctor visits, most people with colds do not need to be seen by a doctor.

Symptoms of a cold can be felt about one to four days after catching a cold virus. This time period is also when an infected person is most contagious. A scratchy or sore throat is often the first symptom of a cold and is gradually followed by sneezing, runny or congested nose. Nasal discharge may be clear, cloudy, yellow or green. Other symptoms of a cold may include: mild fever, feeling tired and sleepy, headache; postnasal drip, throat clearing, cough; and sometimes hoarse voice, watery eyes, and swollen lymph nodes in the neck.

There is no cure for a cold and most people recover within about seven to 10 days. Colds generally do not result in serious health problems, such as pneumonia, bacterial infections or hospitalization. Elderly persons and individuals with a weakened immune system are at higher risk of developing complications.



According to the CDC, between five percent and 20% of the U.S. population comes down with the flu each year, and as many as 200,000 people are hospitalized for flu-related complications. There are two main types of flu virus – Types A and B – that routinely spread in people and are responsible for seasonal flu epidemics each year. The flu viruses are constantly changing. Vaccines are given each fall to protect against the flu virus strain expected to cause the most illness that year.

Flu is different from a cold in many ways. It can cause mild to severe illness, and at times can lead to death. The flu usually starts abruptly, with fever, muscle aches, sore throat, and a cough. People who are sick with flu often feel some or all of these symptoms as well: extreme exhaustion and fatigue for several days or weeks; headache; runny or stuffy nose; sneezing at times; and vomiting and diarrhea. Special tests are usually conducted within the first few days of illness to confirm if a person has the flu.

Symptoms of the flu develop usually about two days after exposure to the virus but can range from one to four days. Adults can be infectious from one day before symptoms develop and up to five to seven days after symptoms start. Young children can be infectious for seven or more days after onset of symptoms. Fever and body aches usually last for three to five days, but cough and fatigue may last for two weeks or more. Although most people are sick with the flu for only a few days, some have a much more serious illness. They may need to go to the hospital. The flu can also lead to pneumonia and death.

Regardless of suspected illness type, call 911 if there is severe difficulty in breathing including struggling for each breath, unable to speak or cry because of difficulty breathing and making grunting noises with each breath, or extreme weakness such as inability to stand. Also, seek medical attention if there is difficulty in breathing and it is not from a stuffy nose, a fever is present for more than three days or temperature is higher than 103° F, or feel weak or very sick.

El Camino Health has emergency rooms located in Los Gatos and Mountain View. To find a primary care physician affiliated with El Camino Health, call 408-540-6645 or search online.


This article first appeared in the February 2019 edition of the HealthPerks newsletter.