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COVID-19 Information: Santa Clara County and Bay Area, California

Trustworthy information about COVID-19

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What are the Symptoms of COVID-19?

Diagnosing COVID without a test is bewildering, because there are so many possible symptoms (one ongoing study in the UK identified over 20!). It is possible that symptoms could also vary depending on whether the person is unvaccinated, was vaccinated, or had a booster.

Some symptoms may be more common in one variant of SARS-CoV-2 than another. For example, perhaps because the omicron variant tends to infect cells in the throat and nasal passages at first (as opposed to other variants that went deep into the lungs), people report more sore throats, sneezing, and runny or stuffy noses than people infected with earlier variants.


This chart illustrates how confusing it can be to tell whether it's a cold, allergy, flu or COVID:

Symptoms of cold, flu, and COVID

Source: Kaiser Permanente, Dec. 28, 2021.

But here are the most common symptoms reported in November in the UK, when most cases are from the omicron variant and with a significant number of people vaccinated:

Omicron symptoms reported in the UK dec. 2021

Source: ZOE COVID Study [UK], Nov. 18, 2021

People ill with COVID-19 might not have all those symptoms, and some have no symptoms at all. When in doubt, get a test to be sure.

What are the Danger Signs?

The Centers for Disease Control warns to get medical treatment immediately if these symptoms appear:

  • trouble breathing
  • persistent pain or pressure in the chest [or back]
  • new confusion, or inability to arouse
  • bluish lips or face. [or very low oxygen, measured by a pulse oximeter, without difficulty breathing]

What To Do If You're Exposed

The current omicron variant spreads faster and further than earlier versions of this disease, which means a lot more people will need to take precautions if they were close to someone infected.  Advice from the Santa Clara County Public Health Department on what to do if you've been in close contact with someone infected is slightly different, depending on vaccination status:

Not vaccinated? Vaccinated more than 6 months ago, but not yet boosted? Follow these directions:

what to do if exposed to COVID and not fully vaccinated

when to end quarantine

If your vaccinations are up-to-date and recent:

What to do if exposed and fully vaccinated

What if I test positive, or have symptoms?

What to do if test positive for COVID

Uh oh, now feeling sick ...

What to do if develop symptoms of COVID

Don't wait to get medical attention if symptoms are severe (see Danger Signs, above).

Guidelines for how long to isolate if you have (or suspect you have) COVID have recently changed. Santa Clara County Public Health has collected comprehensive updated advice on these webpages:

Before showing up at a medical facility, check in first. If your health plan offers medical advice by telephone, call them. If you don't have that option, don't just show up at an urgent care or emergency room -- call ahead, if possible, to let them know it's suspected COVID-19. It is vital that health facilities have time to prepare before you arrive, to protect staff and the other patients from potential infection. 

If you feel sick and do not have health insurance at present, call your local county public health department  for instructions.

What if I'm not that sick? People with mild or moderate symptoms of COVID-19 can take steps to manage this disease (supportive care) while staying home. Seek medical attention ASAP if any of the danger signs of severe disease are present, though.

Supportive care includes:

  • lots of rest;
  • stay hydrated (drink lots of liquids); and
  • use acetaminophen (Tylenol) to lower a fever or relieve pain as needed.

The antiviral medication Paxlovid has been shown to reduce the severity of COVID symptoms, and to shorten how long symptoms last. Don’t delay: Treatment must be started within days of when you first develop symptoms to be effective. It is especially recommended for the most vulnerable:

  • people over 50
  • people with diabetes, heart conditions, disabilities, serious or chronic illness (See this more complete list)

However, in some cases, people who took this medication develop rebound infections, both symptomatic and asymptomatic. Since even asymptomatic rebound infections can spread the disease, it is wise to continue to test for another 5 days up to one week after recovery, and to wear a mask during that time when around other people.

In rare cases, SARS-CoV-2 has been discovered in sick pets. Currently, the CDC advises:

What if someone in my household has COVID?

If you are sharing a home with someone who has COVID-19, do your best to isolate them in the home away from everyone else. If they can't be in a room by themselves, with a door that closes, see if they can have a bed to themselves, with screens or curtains or furniture to separate them from other people in the home. Sick people should wear masks to avoid sharing the virus. Eating alone (not sharing meals with other people), and carefully washing dishes and utensils afterwards will help slow the spread.

If one person in the household is sick, it is highly likely that unvaccinated people sharing that space are sick, too, or will soon be. Everyone in that household should self-quarantine as best they can.

People sharing that home who are fully vaccinated (had initial vaccine plus any boosters for which they are eligible) can also become infected, although they are less likely to become sick. They do not need to self-quarantine if they test negative. However they would be wise to wear a mask to protect themselves and others, and to test with a home antigen test every 3-5 days until the sick person has fully recovered.

Since people can continue to shed coronavirus even after they start to feel better, it's safest to follow the CDC precautions for 5-7 days afterwards. Later, if someone else in the household gets sick, that resets the self-quarantine clock for everyone in that household.

What if I'm Pregnant, or Have a Newborn?

If you can, get vaccinated and boosted ASAP!

Reports have found that the risk of adverse effects to both mothers and babies is extremely low when mothers get vaccinated -- but both face much greater risks if mothers get seriously ill with COVID while pregnant.  (See the page on Vaccines in this guide for more details on getting vaccinated while pregnant or breastfeeding.)

The CDC's guidance includes advice on pregnancy and delivery, on breastfeeding mothers with suspected or confirmed COVID-19 infections, and on new baby care during this pandemic.

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