A blood clot can cause a range of symptoms depending on where it forms. If you notice possible signs, seek medical care promptly, especially if symptoms are new, worsening, or involve trouble breathing, chest pain, or sudden weakness. Key warning signs by location

• Legs or arms (deep vein thrombosis or DVT): sudden leg or arm pain, swelling, warmth, or redness; leg feels heavy or tender, usually in one limb.
• Lungs (pulmonary embolism or PE): sudden shortness of breath, chest pain that may worsen with deep breaths, rapid or irregular heartbeat, coughing up blood, feeling lightheaded or faint.
• Brain (stroke): sudden trouble speaking or understanding speech, sudden weakness or numbness on one side of the body, face drooping, sudden severe headache.
• Heart or chest not related to PE (possible heart-related clot): chest discomfort, shortness of breath, dizziness, sweating, nausea.
• Abdominal symptoms: intense or persistent belly or back pain, sometimes with swelling or vomiting, though this is less common for clots.

Immediate actions

• If you have sudden chest pain, trouble breathing, new weakness on one side, trouble speaking, or severe headache, call emergency services right away.
• If you suspect a DVT (leg swelling/pain) but no breathing problems, contact a healthcare provider promptly for evaluation; they may order ultrasound or blood tests.
• Do not ignore symptoms, especially if you have risk factors: recent surgery or hospitalization, prolonged immobility, pregnancy, oral contraceptives or hormone therapy, smoking, cancer, obesity, or a family history of clotting disorders.

What to expect in medical evaluation

• A clinician may review symptoms, risk factors, and perform physical exams.
• Tests may include ultrasound of the affected limb, blood tests (e.g., D-dimer), CT scans or other imaging to locate clots, and assessment of oxygen levels and heart function.

Preventive and management notes

• If a clot is confirmed, treatment often includes anticoagulant (blood-thinning) medications to prevent growth and new clots, and sometimes procedures or devices if clots are large or in critical areas.
• For prevention, staying active, moving during long trips, maintaining a healthy weight, not smoking, and following medical guidance on medications or hormonal therapies can help reduce risk.

If you’d like, share where you’re experiencing symptoms (e.g., leg, chest, brain) and any risk factors you have, and a more tailored overview of what doctors would check for you can be outlined.