What are the symptoms of lung cancer?

Lung cancer is the leading cause of cancer death in the U.S., largely because it's usually caught late. The tricky part: early lung cancer often has no symptoms at all, and when symptoms do appear they look like a bad cold, seasonal allergies, or reflux. This guide walks through what the symptoms actually are, which ones deserve a call today, and what screening looks like for people at higher risk.

The most common symptoms — in plain language

Not everyone has all of these, and having one doesn't mean you have cancer. These are the signs pulmonologists and oncologists ask about first.

• A cough that lasts more than 3 weeks, or an old smoker's cough that suddenly changes — deeper, wetter, more frequent.
• Coughing up blood or rust-colored sputum — even a small streak, even once.
• Shortness of breath that's new, or getting worse with everyday activities.
• Wheezing that's new for you.
• Chest, shoulder, or upper-back pain that's worse with deep breathing, coughing, or laughing.
• Hoarseness or a change in your voice that doesn't clear in 2 to 3 weeks.
• Repeated chest infections — pneumonia or bronchitis that keeps coming back in the same spot.
• Unexplained weight loss, loss of appetite, or fatigue.
• A swollen face, neck, or arm (less common — can signal a tumor pressing on a large vein).

Takeaway: it's rarely one dramatic symptom. It's usually a cough that overstays its welcome.

Which symptoms need a doctor call today

• Coughing up any amount of blood.
• A cough lasting more than 3 weeks — especially if you smoke or used to.
• Sudden or worsening shortness of breath.
• Chest pain that's sharp with breathing.
• Repeat pneumonia in the same lobe.
• Unexplained weight loss over 10 pounds.

The next step is usually a call to your primary care doctor, who will order a chest X-ray and, if anything looks suspicious or you're at higher risk, a low-dose CT scan of the chest.

Takeaway: any blood in the sputum, a cough over 3 weeks, or repeat pneumonia in the same spot are the three findings doctors take most seriously — especially in current or former smokers.

Symptoms by stage

• Stage 0 to I: often no symptoms at all. Found on a screening low-dose CT.
• Stage II: a persistent cough, occasional blood-tinged sputum, mild shortness of breath.
• Stage III: more consistent cough, chest pain, hoarseness, swollen lymph nodes above the collarbone.
• Stage IV (spread beyond the lung): symptoms depend on where — bone pain, headaches, seizures, jaundice, weight loss.

Takeaway: by the time lung cancer causes obvious symptoms, it's often stage III or IV. Low-dose CT screening is the only reliable way to catch it early.

Who is at higher risk

• Current or former smokers, especially with a 20 pack-year history (a pack a day for 20 years, or two packs a day for 10).
• Age 50 to 80.
• Long-term exposure to secondhand smoke, radon, asbestos, diesel exhaust, or certain industrial chemicals.
• A family history of lung cancer in a parent or sibling.
• Prior radiation therapy to the chest (for lymphoma or breast cancer).
• A personal history of COPD or pulmonary fibrosis.

You don't have to smoke to get lung cancer — roughly 10 to 20% of U.S. cases occur in people who never smoked.

Takeaway: if you're 50 to 80 with a 20 pack-year history, ask about a screening low-dose CT — it's covered by Medicare and most insurance.

What screening actually looks like

• Low-dose CT (LDCT) — the only screening test proven to reduce lung cancer deaths. Annual, for adults 50 to 80 with a 20+ pack-year history who currently smoke or quit within the last 15 years.
• Chest X-ray — not recommended for routine screening; misses too many early cancers.
• Sputum cytology — no longer recommended for screening.

If a low-dose CT finds a nodule, the next step depends on size: watchful CT follow-up for small nodules, PET scan or biopsy for larger or suspicious ones.

Takeaway: LDCT screening is dramatically underused — fewer than 6% of eligible Americans get it. If you're eligible and haven't been offered it, ask.

What to do if you have symptoms

1. Write down what you've noticed — when the cough started, whether you've coughed up any blood, how far you can walk before getting winded.
2. Call your primary care doctor for an appointment this week. Say "I have a cough that's lasted X weeks and I'd like a chest X-ray."
3. If you're a current or former smoker, ask about a low-dose CT — a plain chest X-ray can miss early lung cancer.
4. Don't accept a repeat course of antibiotics for a lingering cough without imaging. Bronchitis and pneumonia should improve — a cough that doesn't needs a look, not another Z-Pak.
5. Bring someone with you. Two people hear more than one.

If you're diagnosed, our guide to what to do in the first 72 hours after a cancer diagnosis walks through the exact order of steps. And if your first appointment left you with a report full of words you don't understand, how to read a pathology report you don't understand is a plain-language walkthrough.

Takeaway: most people who go in with a lingering cough don't have cancer. But the ones who do have a five-year survival above 60% when caught at stage I — and under 10% at stage IV. Early imaging is the whole game.

Related reading

• Just diagnosed with cancer: what to do first — the first 72 hours, in order.
• How to read a pathology report you don't understand — a plain-language walkthrough.
• Questions to ask after any new diagnosis — the full framework for the first real appointment.

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This post is for general informational purposes and isn't a substitute for guidance from your care team. If you have symptoms that concern you, call your doctor.