23 January 2026

How to Use the Stethoscope in Quarantine Zone: The Last Check

By newsgame

The Stethoscope is one of many tools used to detect symptoms in Quarantine Zone: The Last Check, with players looking for black spots and listening to the lungs of survivors. Compared with simpler tools, it can be a little bit tricky to understand, and as only one breathing symptom is known at first, there are two more Stethoscope symptoms to research using the Laboratory.

Quarantine Zone The Last Check - Beginner Tips

Beginner Tips for Quarantine Zone The Last Check

To keep your checkpoint running and save as many lives as possible, consider the following beginner tips for Quarantine Zone: The Last Check.

Survivors who cough are more likely to have problems with their lungs, so make sure to thoroughly test them with the Stethoscope.

How To Use The Stethoscope In Quarantine Zone: The Last Check

Quarantine Zone The Last Check - Stethoscope - Healthy Lungs

The only control for using the Stethoscope in Quarantine Zone: The Last Check is to hold it down to make it work.

PC: LMB
Xbox: RT
PlayStation: R2

Looking For Black Zones

Quarantine Zone The Last Check - Stethoscope - Black Zones on Lungs

The first step with the Stethoscope is to look for any black zones on the lungs. While hovering over these, they may disappear, meaning that the specific spot is fine. Visually, black zones are the only thing to look out for.

Black zones can also appear on the back, so make sure to walk around the survivor, making sure nothing is missed.

However, this doesn’t mean that all black zones will disappear, so keep looking. If any black zones remain after being examined, it is a symptom. If all black zones disappear, the survivor doesn’t have a lung problem.

Listening To Black Zones & Looking For High Frequencies

Quarantine Zone The Last Check - Stethoscope - Listening To Black Zones

Once a lingering black zone is found, players will now need to examine it. They should notice high amplitude waves on the Stethoscope, but the main clue comes from listening to the survivor breathing while hovering over these black zones.

Listen to them, and then listen to the examples in the symptoms chart to compare. Only Sickly Breath is known at first, so if it matches, select this, but if you hear a new sound, send the survivor to the lab for testing, hopefully discovering a new lung symptom.

Quarantine Zone The Last Check - How to Get More Syringe Analyzers

How to Get More Syringe Analyzers in Quarantine Zone The Last Check

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Stethoscope Upgrades In Quarantine Zone: The Last Check

Tools can be upgraded in Quarantine Zone using Research Points, and there happen to be three upgrades for the Stethoscope, one of which makes using it much easier.

Zone Level	Upgrade	Description	Research Points
III	Stethoscope: Color Indicator	Adds a color filter for normal, nonspecific, and infected sounds.	100 RP
III	Stethoscope: Amplified Sensors	Tuned sensors for enhanced audio clarity and enlarged black zones.	100 RP
V	Stethoscope: Smart Filter	Removes irrelevant black zones.	150 RP

The best of these, and the biggest priority, is the Color Indicator, as the sound no longer matters as much. With this unlocked, hovering over a black spot and looking at the color is all that’s needed.

Green (Low Frequency): Healthy
Green (High Frequency): Sick
Yellowish Green: Sick or Infected
Red: Infected

The Smart Filter is also great, as only relevant black zones will appear, meaning less time is wasted. However, this upgrade can only be unlocked later on in the game.

Quarantine Zone The Last Check - All Symptoms

All Symptoms & What They Look Like in Quarantine Zone: The Last Check

Find out what every single symptom looks like in Quarantine Zone: The Last Check.

All Stethoscope Symptoms In Quarantine Zone: The Last Check

Quarantine Zone The Last Check - Symptoms - Appearance Stethoscope

Sickness	Undetermined	Infected
Sickly Breath	Nonspecific Respiration	Infected Breath

At first, players will only be aware of the Sickly Breath symptom, but there are more to be found, bringing the total to three. The black zones won’t look any different for each of these symptoms, so it’s all down to listening and using the Color Indicator upgrade.

Sickly Breath – Sickness

Quarantine Zone The Last Check - Symptoms - Sickly Breath

A Sickly Breath will cause a low wheezing sound and will display bright green with the color upgrade.

Nonspecific Respiration – Sickness Or Infection

Quarantine Zone The Last Check - Symptoms - Non-Specific Respiration

Nonspecific Respiratory symptoms mean that the survivor will wheeze while inhaling, but exhale silently.

It’s hard to differentiate between Nonspecific Respiration and the Sickly Breath, so get the Color Indicator upgrade and look for it turning a more yellowish green.