Top Red Flags in Patient Conditions Every Nurse Should Watch For

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May 7
3 min read

Early detection can make the difference between stabilization and rapid deterioration. According to the American Association of Critical-Care Nurses (AACN), about 70% of in-hospital cardiac arrests occur in patients who had documented signs of clinical deterioration in the hours leading up to the event. Nurses are often the first line of defense when patients show subtle — and not-so-subtle — signs of declining health. Below, we explore the most critical warning signs nurses should always monitor.

Top Red Flags in Patient Conditions Every Nurse Should Watch For

1. Sudden Changes in Mental Status

Altered mental status is one of the most important red flags to recognize, and often one of the earliest signs of a serious issue. Confusion, disorientation, and agitation are early signs of hypoxia, sepsis, or metabolic imbalances.

Watch for:

New onset of confusion or delirium
Changes in speech, memory, or alertness
Restlessness or unexplained agitation

These shifts are sometimes misattributed to fatigue or age, which is why consistent baseline assessments and communication with the healthcare team are crucial.

2. Abnormal Vital Signs — Even Slightly

While critical thresholds (like a blood pressure below 90/60 mmHg or oxygen saturation under 90%) are obvious alerts, trends in vital signs matter even more. A slight rise in respiratory rate or a gradual drop in blood pressure may precede cardiac arrest, shock, or respiratory failure.

Watch for:

Tachycardia (>100 beats per minute) may indicate early signs of shock, dehydration, fever, or hypoxia.
Bradycardia (<60 beats per minute) could be linked to medications, hypothermia, or a prelude to cardiac arrest.
Hypotension trending downward, suggesting internal bleeding or fluid loss
Low oxygen saturation despite oxygen therapy

3. Chest Pain — Especially When Accompanied by Other Symptoms

Not all chest pain is cardiac, but it should never be ignored. When paired with symptoms like shortness of breath, nausea, diaphoresis, or radiating arm/jaw pain, chest discomfort could signal myocardial infarction or pulmonary embolism.

Watch for:

Crushing, burning, or pressure-like chest pain
Pain radiating to the back, neck, shoulder, or arm
Shortness of breath, especially at rest

Even if a patient has a history of GERD or anxiety, new or worsening chest pain should be treated as cardiac until ruled out.

4. Decreased Urine Output

Urine output is a direct window into a patient’s renal and circulatory health. A drop in urine production may signal dehydration, shock, acute kidney injury, or worsening heart failure.

Watch for:

Urine output is less than 30 mL/hr
Dark, concentrated urine
New incontinence or retention in previously stable patients

Consistent monitoring and trending of intake/output is essential, especially in post-op patients, those with heart or kidney disease, and the elderly.

5. Uncontrolled Pain

Uncontrolled pain can indicate a worsening condition, post-op complication, infection, or poor healing.

Watch for:

New pain or change in character (e.g., sharp to burning)
Pain that doesn't respond to ordered medications
Pain paired with swelling, redness, or numbness

Ignoring pain can delay diagnosis and erode trust. Nurses are vital in advocating reassessment and re-intervention when pain seems disproportionate or unexplained.

6. Bleeding — Obvious or Hidden

Any active bleeding requires immediate attention, but hidden or slow bleeds can be more dangerous. GI bleeding, for instance, may not be visible but presents with hypotension, tachycardia, or dark stools.

Watch for:

Hematuria or blood in stool/vomit
Easy bruising or petechiae (suggesting clotting disorder or medication reaction)
Drop in hemoglobin or hematocrit without overt signs

Nurses should also be on alert for patients on anticoagulants, post-surgical patients, or those with liver disease, as they’re at higher risk for internal bleeding.

Final Thoughts

Recognizing red flags in patient conditions requires critical thinking, vigilance, and confidence. When something feels "off," it usually is. Don’t underestimate the power of gut instinct, pattern recognition, and early intervention.