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Dr. Mohammadreza Dabiriفارسی
Questions and answers

What are the symptoms of stomach cancer?

From simple indigestion to warning signs; when to see a doctor and have an endoscopy

Updated: 28 October 20261 min read7 references
Short answer

Stomach cancer usually has no symptoms in its early stages, or its symptoms are like indigestion, bloating after meals, mild nausea, loss of appetite and heartburn [1]. In more advanced stages, unexplained weight loss, vomiting, blood in the stool (black stools), stomach pain, difficulty swallowing, jaundice and fluid in the abdomen may occur [1]. In most people these symptoms have benign causes; but if they persist or come with warning signs, see your doctor for assessment and probably an endoscopy.

Key points

  • Finding stomach cancer early is difficult [1], and many patients are diagnosed at an advanced stage [2].
  • A firm diagnosis is only possible with endoscopy and biopsy [2].
  • The Maastricht VI guideline recommends treating everyone with Helicobacter pylori infection, and preventing stomach cancer is one of its aims [3].
  • Stomach cancer rates vary widely around the world; in one high-risk region, Golestan Province in northern Iran, the age-standardised incidence in the cancer registry (2004 to 2016) was 26.9 per 100,000 in men and 12.2 in women [5].

Symptoms of stomach cancer and what they may mean

SymptomUsually seen at which stageWhat to do
Indigestion and stomach discomfortA possible early symptom; but very common and often unrelated to cancer [1]If it continues despite treatment or comes with warning signs, see your doctor
Feeling bloated after mealsA possible early symptom [1]If it lasts several weeks, talk to your doctor
Mild nausea, loss of appetite, heartburnPossible early symptoms [1]If they persist or come with weight loss, see your doctor
Unexplained weight lossMostly in advanced stages [1]See a doctor as soon as possible
VomitingMostly in advanced stages [1]Repeated or bloody vomiting: seek care straight away
Blood in the stool (black, tarry stools)Mostly in advanced stages [1]Seek care straight away
Stomach painMostly in advanced stages [1]Have persistent or severe pain checked
Difficulty swallowingMostly in advanced stages [1]See a doctor as soon as possible
Yellowing of the skin and eyes, fluid in the abdomen (ascites)Advanced stages [1]Seek care straight away

This table does not replace an examination by a doctor; in most people these symptoms have a benign cause.

If the doctor suspects stomach cancer, which tests are needed?

  1. 1

    Endoscopy and biopsy

    Looking directly at the oesophagus and stomach and taking a sample from the suspicious area; the diagnosis is confirmed by examining the tissue [2].

  2. 2

    Testing for Helicobacter pylori

    If positive, the infection is treated [3].

  3. 3

    CT scan

    If cancer is confirmed, a CT scan of the chest, abdomen and pelvis is done to check whether the disease has spread [2, 4].

  4. 4

    Further tests

    Endoscopic ultrasound (EUS) to find the depth of the tumour and, in selected cases, PET-CT [2]; and testing biomarkers such as HER2, MSI and PD-L1 to choose treatment [4].

When should I call my doctor?

Indigestion is very common and in most cases has no dangerous cause. But if it does not go away despite medicine, or it comes with unexplained weight loss, repeated vomiting, difficulty swallowing or black stools, do not wait; see your doctor. If the cause is stomach cancer, ignoring the symptoms delays treatment and makes it less effective [1].

Vomiting blood, or black stools with dizziness or severe weakness, needs urgent care at an emergency department.

Related questions

I always have heartburn; could it be cancer?

Heartburn and indigestion are very common and in most people have a benign cause, although they can also be early symptoms of stomach cancer [1]. If the symptoms are new, do not improve with treatment or come with weight loss, vomiting or black stools, see your doctor.

Can a blood test or tumour marker diagnose stomach cancer?

No. The diagnosis is made with endoscopy and biopsy [2]. Markers such as CA 19-9 are used mainly to check how treatment is working, not for diagnosis [6]. Read more: What is a tumour marker?

What should I do if a relative has had stomach cancer?

Talk to your doctor about a Helicobacter pylori test. In a rigorous study of first-degree relatives of patients with stomach cancer, treating Helicobacter infection lowered the risk of stomach cancer [7].

Related cancer types

Stomach cancer

Related questions

Can cancer be prevented?Does opium cause cancer?Should I be tested for H. pylori? (Preventing stomach cancer)Do red meat and processed meat cause cancer?Does hookah (shisha, waterpipe) cause cancer? Is it safer than cigarettes?Is cancer contagious?

References

7 references
Show all references, 5 with a study cardClose the reference list

Numbers in the text, such as [1], refer to these sources. Sources with a “Study card” button are summarised in the site’s evidence library.

  1. 1
    Stomach Cancer SymptomsNational Cancer Institute · cancer.gov
    Source Back to text: 1 2 3 4 5 6 7 8 9 10 11 12 13 14
  2. 2
    Gastric cancerSmyth EC, Nilsson M, Grabsch HI, van Grieken NC, Lordick F · Lancet · 2020;396:635-648
    Study cardDOIPubMed Back to text: 1 2 3 4 5 6
  3. 3
    Management of Helicobacter pylori infection: the Maastricht VI/Florence consensus reportMalfertheiner P, Megraud F, Rokkas T, Gisbert JP, Liou JM, Schulz C, et al · Gut · 2022;71:1724-1762
    Study cardDOIPubMed Back to text: 1 2
  4. 4
    Gastric cancer: ESMO Clinical Practice Guideline for diagnosis, treatment and follow-upLordick F, Carneiro F, Cascinu S, Fleitas T, Haustermans K, Piessen G, et al · Ann Oncol · 2022;33:1005-1020
    Study cardDOIPubMed Back to text: 1 2
  5. 5
    Trends in the Incidence of Stomach Cancer in Golestan Province, a High-risk Area in Northern Iran, 2004-2016Ghasemi-Kebria F, Amiriani T, Fazel A, Naimi-Tabiei M, Norouzi A, Khoshnia M, et al · Arch Iran Med · 2020;23:362-368
    Study cardDOIPubMed Back to text
  6. 6
    Tumor Markers in Common UseNational Cancer Institute · cancer.gov
    Source Back to text
  7. 7
    Family History of Gastric Cancer and Helicobacter pylori TreatmentChoi IJ, Kim CG, Lee JY, Kim YI, Kook MC, Park B, et al · N Engl J Med · 2020;382:427-436
    Study cardDOIPubMed Back to text

This page is based on reputable scientific sources and was last updated on 28 October 2026. The content of this website is for educational and informational purposes only and does not replace consultation, diagnosis or treatment by a specialist physician. Consult your treating physician about any treatment decision.

Printed from the website; the full and up-to-date version: https://drdabiri.com/en/questions/symptoms-of-stomach-cancer/

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Stomach cancerRisk factors (Helicobacter pylori and salt), warning signs, endoscopy, staging and the latest treatments, including FLOT, immunotherapy, anti-HER2 drugs and newer targeted drugs. 26 October 2026 Should I be tested for H. pylori? (Preventing stomach cancer) If a first-degree relative has had stomach cancer, get tested for Helicobacter pylori, and if positive, finish the treatment and test again. Treating this germ cut the risk of stomach cancer by more than half. 1 Rank of stomach cancer among cancer deaths in Iran 19 October 2026 Is cancer contagious? No; cancer is not contagious and is not passed on through everyday contact. Some contagious infections such as HPV and hepatitis B raise the risk of cancer, but the cancer itself is not passed on.