Now that flu season has arrived, it may be hard to differentiate the symptoms of a typical flu from other health threats such as the COVID-19 pandemic and Lyme disease. The three conditions are all caused by different things, but can have eerily similar symptoms that make it difficult to determine what exactly is going in your body when you start to feel ill.
That being said, there are some ways to tell the three conditions apart. Since treatments vary significantly (as well as the potential outcomes of each type of infection), it’s important to be able to make the distinction. So, what are the symptoms of COVID-19, flu, and Lyme disease, and what can you do to tell them apart if you happen to fall ill? Read on to learn all you need to know.
What do the early symptoms of COVID-19 infection feel like?
COVID-19 has a varied list of symptoms. If you contract the infection, you’re unlikely to experience every symptom at once. Because of this, it can be difficult to know whether you should seek out testing, stay home and self-manage the symptoms until the infection clears, or head to your nearest emergency department.
Since COVID-19 infections range from asymptomatic to severe, knowing the early signs can make a huge difference in how the infection takes its course. Some of the most common early symptoms of COVID-19 include:
- Fever
- Cough
- Tiredness
- Loss of taste or smell

Some less common symptoms of COVID-19 include:
- Sore throat
- Headache
- Aches and pains
- Diarrhea
- A skin rash
- Discoloration of the fingers or toes
- Eye redness and irritation
Many of these symptoms are either non-specific or mimic other types of conditions. For example, eye redness and irritation, headache, diarrhea, and fever could all be caused by a variety of things and aren’t just indictive of COVID-19. The same can be said for both the flu and Lyme disease.
What are the early symptoms of Lyme disease?
The early symptoms of Lyme disease are similar to many that may be experienced with COVID-19. The symptoms most often seen in people with the bacterial Lyme infection include:
- A rash that can sometimes be shaped like a bullseye
- Fever
- Chills
- Headache
- Fatigue
- Muscle and joint aches
- Swollen lymph nodes
If Lyme is left untreated, other symptoms can also occur such as severe headaches, skin rashes, heart and neurological disorders, and arthritis.
What are the early symptoms of the flu?
The flu is a highly common illness and presents similarly to both the early symptoms of Lyme disease and COVID-19. People who get the flu typically experience non-specific symptoms such as:
- Fever
- Chills
- Cough
- Sore throat
- Runny or stuffy nose
- Muscle or body aches
- Headaches
- Fatigue
- Vomiting and diarrhea (more common in children and less likely in adults)
As you can see, all three infections have crossover symptoms.
What symptoms occur in COVID-19, flu, and Lyme disease?
While all three infections are caused by different pathogens, they can all present with:
- Headaches
- Fever
- Muscle aches
- Fatigue
These symptoms, however, are where the crossovers tend to stop. When you’re considering a COVID-19 infection and have all the aforementioned symptoms, you will also want to consider the other symptoms of COVID-19 as well. One markedly specific symptom of COVID-19 is a loss of taste and smell, which does not occur with Lyme disease or the flu.
When it comes to the flu, a runny or stuffy nose could be a good indicator that you do not have Lyme disease or a COVID-19 infection, as those two infections do not typically present with that symptom.
Lyme disease, although harder to diagnose because of its non-specific symptoms, has a couple of key indicators such as a bullseye rash at the site of the tick bite and swollen lymph nodes. That being said, swollen lymph nodes are a very rare side effect of a COVID-19 infection, so it may be helpful to get checked for both Lyme disease and COVID-19 if that symptom is present.

How to differentiate between COVID-19, flu, and Lyme disease
Besides looking at specific symptoms, you can also use your own lifestyle as a way to determine the most likely explanation for your symptoms. For example, if you tend to interact with only a small group of people and hike in wooded areas a lot, there’s a good chance that your symptoms stem from Lyme disease rather than one of the other two infections.
Community transmission of the flu and COVID-19 is the highest reason for the spread, so if you haven’t been around anyone with either, it’s unlikely that you have one of these conditions. On the other hand, if you spend a lot of time with others (especially without social distancing) and are rarely in areas where ticks are prevalent, it’s unlikely that you have Lyme disease.
COVID-19, flu, and Lyme disease can all lead to serious and severe complications. This means that no matter what, you should always see your doctor if you present with any of the aforementioned symptoms. Being safe when it comes to all three infections could mean the difference between severe and debilitating illness and a quick recovery.
Featured image by Andrea Piacquadio on Pexels