What are the signs and symptoms to be mindful of in a patient taking anticoagulants (blood thinners), such as warfarin, aspirin, clopidogrel, apixaban, rivaroxaban, or dabigatran?

Warning Signs and Symptoms While Taking Blood Thinners

Patients on anticoagulants must immediately report any unusual bleeding, severe headache, vision changes, weakness, numbness, or signs of hemodynamic instability, as these may indicate life-threatening hemorrhage requiring emergent medical attention. 1

Critical Bleeding Signs Requiring Emergency Care

Neurological Symptoms (Intracranial Hemorrhage)

• Unusually intense headache that is different from typical headaches 1
• Sudden vision changes, blurred vision, or blindness (may indicate intraocular bleeding) 1
• Weakness, numbness, or paralysis on one side of the body 1
• Confusion, altered consciousness, or difficulty speaking (aphasia) 1
• Loss of balance, difficulty walking (ataxia), or vertigo 1
• Seizures or vomiting associated with severe headache 1

Hemodynamic Instability Indicators

• Increased heart rate (tachycardia) - often the first sign of significant blood loss 1
• Systolic blood pressure <90 mm Hg or drop >40 mm Hg from baseline 1
• Orthostatic symptoms: lightheadedness or dizziness when standing, with blood pressure drop ≥20 mm Hg systolic or ≥10 mm Hg diastolic 1
• Decreased urine output (<0.5 mL/kg/h) indicating poor organ perfusion 1

Gastrointestinal Bleeding

• Red, pink, or brown urine 1, 2
• Red or black tarry stools 1, 2
• Vomiting blood or coffee-ground appearing vomit 1, 2
• Severe or persistent abdominal pain with distension 1

Respiratory and Airway Bleeding

• Coughing up blood or blood clots (hemoptysis) 1, 2
• Profuse nosebleeds that don't stop with pressure 1
• Shortness of breath or difficulty breathing 1

Musculoskeletal Bleeding

• Severe joint pain with swelling and decreased range of motion (intra-articular bleeding) 1
• Muscle pain, swelling, pallor, or weakness in extremities (intramuscular bleeding/compartment syndrome) 1
• Back, flank, or hip pain (may indicate retroperitoneal hemorrhage) 1

Common Non-Critical Bleeding Signs

Minor Bleeding That Still Requires Reporting

• Easy bruising or bruises appearing without trauma 1, 2
• Bleeding from gums during tooth brushing 1, 2
• Nosebleeds that occur frequently but stop with pressure 1, 2
• Prolonged bleeding from minor cuts - takes longer than usual to stop 1, 2
• Heavier than normal menstrual bleeding 1, 2

Spinal/Epidural Hematoma Warning Signs

For patients who have had spinal procedures or epidural catheters while on anticoagulation:

• Tingling or numbness, especially in legs and feet 2
• Muscle weakness in lower extremities 2
• Back pain with bilateral leg symptoms 1
• Bowel or bladder dysfunction 1

Additional Symptoms Requiring Medical Evaluation

• Persistent headaches with dizziness or feeling weak 1, 2
• Any bleeding that is unexpected, severe, or cannot be controlled 1, 2
• Symptoms of anemia: extreme fatigue, pale skin, rapid heartbeat at rest 1

Critical Pitfalls to Avoid

• Never dismiss mild symptoms in elderly patients (≥75 years), as they have significantly higher risk of gastrointestinal and intracranial bleeding, particularly with dabigatran and rivaroxaban 1
• Do not ignore seemingly minor bleeding in patients taking concomitant antiplatelet agents (aspirin, clopidogrel), NSAIDs, SSRIs, or SNRIs, as these dramatically increase bleeding risk 1
• Patients with renal impairment (CrCl <30 mL/min) require heightened vigilance, as anticoagulant effects are prolonged 1
• Any hemoglobin drop ≥2 g/dL or requirement for ≥2 units of blood transfusion constitutes major bleeding and is associated with significantly increased mortality risk 1

Patient Education Essentials

• Advise patients to recognize bleeding symptoms and report any unusual bleeding immediately 1
• Instruct patients never to stop anticoagulation without physician guidance, as this dramatically increases stroke risk in atrial fibrillation patients 2
• Warn patients about medication interactions: avoid NSAIDs, aspirin (unless prescribed), and herbal supplements without physician approval 1, 2
• Emphasize that warfarin causes bleeding complications in approximately 29,000 emergency department visits annually and ranks first in drug-related deaths from therapeutic use 3