71 Diseases That Start With The Letter H

Have you ever wondered about diseases that start with the letter “H”? Wonder no more, this article is exactly what you are looking for.

In this article, I will dive into the realm of some known and lesser-known diseases beginning with this enigmatic letter H, aiming to raise awareness and understanding.

So, without any further ado, let’s embark on this fascinating journey and broaden our understanding of diseases that start with the letter H.


Diseases That Start With H

The followings are some known and lesser-known diseases that begin with the letter H (In alphabetical order):

1. Haemophilus Infection: Haemophilus infection is caused by Haemophilus influenzae bacteria and can lead to various illnesses, including pneumonia, meningitis, and ear infections. It is particularly concerning in young children and individuals with weakened immune systems.

2. Haemorrhagic Fever: Haemorrhagic fevers are a group of viral infections that can cause severe bleeding, organ failure, and even death. Examples include Ebola virus disease and Lassa fever.

3. Haemorrhoids (Piles): Haemorrhoids are swollen blood vessels in the rectum or anus that can cause pain, itching, and bleeding. They are common and often result from straining during bowel movements, chronic constipation, or prolonged sitting.

4. Hair Loss: Hair loss, medically known as alopecia, can be caused by various factors, including genetics, hormonal changes, and certain medical conditions. Male-pattern baldness and female-pattern hair loss are common types of hair loss.

5. Hallux Valgus (Bunions): Hallux valgus, commonly known as bunions, is a deformity of the big toe joint that causes the big toe to point towards the other toes. This condition can lead to pain, swelling, and difficulty in wearing certain shoes.

6. Hantavirus Infection: Hantavirus infection is a rare viral disease transmitted to humans through contact with infected rodents or their droppings. It can lead to hantavirus pulmonary syndrome (HPS) or haemorrhagic fever with renal syndrome (HFRS), both of which can be severe.

7. Hashimoto’s Disease: Hashimoto’s disease is an autoimmune condition where the body’s immune system attacks the thyroid gland, leading to hypothyroidism (underactive thyroid). It can cause fatigue, weight gain, and depression.

8. Hay Fever: Hay fever, also known as allergic rhinitis, is an allergic reaction to pollen or other allergens. It can cause symptoms such as sneezing, nasal congestion, and itchy eyes.

9. Head and Neck Cancer: Head and neck cancer refers to various types of cancers that affect the head and neck region, including the mouth, throat, voice box, and nasal cavity.

10. Head Lice and Nits: Head lice are tiny parasitic insects that infest the scalp and hair. Nits are the eggs laid by head lice. Infestations can cause itching and discomfort.

11. Headaches: Headaches can occur due to various reasons, including tension, migraines, sinusitis, and underlying medical conditions. They can cause pain and discomfort in the head.

12. Hearing Loss: Hearing loss can result from aging, exposure to loud noises, infections, or genetic factors. It can range from mild to profound and may lead to communication difficulties.

13. Heart Attack: A heart attack, also known as a myocardial infarction, occurs when the blood flow to the heart is blocked, leading to damage to the heart muscle. Symptoms include chest pain, shortness of breath, and pain in the arm or jaw.

14. Heart Disease: Heart disease is a broad term that includes various conditions affecting the heart, such as coronary artery disease, heart failure, and arrhythmias.

15. Hemangioma: Hemangiomas are non-cancerous growths of blood vessels that often appear as red or purple marks on the skin. They are common in infants and usually resolve on their own over time.

16. Hematuria (Blood in Urine): Hematuria is the presence of blood in the urine and can indicate various underlying conditions, including kidney stones, urinary tract infections, or kidney diseases.

17. Hemianopsia: Hemianopsia is a visual impairment where half of the visual field is lost in one or both eyes. It can result from brain injuries or strokes.

18. Hemifacial Spasm: Hemifacial spasm is a neurological disorder characterized by involuntary muscle contractions on one side of the face.

19. Hemiplegia: Hemiplegia refers to paralysis of one side of the body, typically caused by a stroke or brain injury.

20. Hemolytic Anemia: Hemolytic anemia is a condition where the body destroys red blood cells faster than it can produce them, leading to a shortage of healthy red blood cells.

21. Hemophagocytic Lympho Histiocytosis (HLH): HLH is a rare and life-threatening condition where certain immune cells overreact and attack healthy tissues and organs.

22. Hemophilia: Hemophilia is a genetic disorder that affects blood clotting, leading to prolonged bleeding and bruising.

23. Hemorrhoids: Hemorrhoids are swollen blood vessels in the rectum or anus that can cause pain and discomfort.

24. Hepatic Encephalopathy: Hepatic encephalopathy is a condition that occurs when the liver fails to remove toxins from the blood, leading to brain function impairment.

25. Hepatitis: Hepatitis refers to inflammation of the liver and can be caused by viral infections (hepatitis A, B, C, D, and E) or other factors like alcohol consumption or certain medications.

26. Hepatitis A: Hepatitis A is a viral infection that spreads through contaminated food or water, causing liver inflammation.

27. Hepatitis B: Hepatitis B is a viral infection transmitted through infected blood, sexual contact, or from mother to child during childbirth. It can lead to chronic liver disease.

28. Hepatitis C: Hepatitis C is a viral infection transmitted through contact with infected blood. It can cause chronic liver disease and may lead to liver cirrhosis or cancer.

29. Hepatitis E: Hepatitis E is a viral infection transmitted through contaminated food or water and can cause acute liver disease.

30. Hernia: A hernia occurs when an organ or tissue pushes through a weak spot in the surrounding muscles or connective tissue.

31. Herpes (HSV): Herpes is a viral infection caused by the herpes simplex virus (HSV) and can lead to cold sores or genital herpes.

32. Herpes Simplex: Herpes simplex is another term used to describe the viral infection caused by the herpes simplex virus (HSV).

33. Hiatus Hernia: Hiatus hernia is a condition where a part of the stomach pushes up into the chest through the diaphragm.

34. Hidradenitis Suppurativa: Hidradenitis suppurativa is a chronic skin condition that causes painful lumps and boils in areas where skin rubs together, such as the armpits and groin.

35. High Blood Pressure: High blood pressure, also known as hypertension, is a condition where the force of blood against the artery walls is consistently too high, which can lead to various health issues.

36. High Cholesterol: High cholesterol refers to elevated levels of cholesterol in the blood, which can increase the risk of heart disease.

37. Hirschsprung’s Disease: Hirschsprung’s disease is a congenital condition where certain nerve cells are missing from the colon, leading to problems with bowel movements. Infants with this condition may have difficulty passing stool and may experience severe constipation.

38. Histiocytosis: Histiocytosis refers to a group of rare disorders where abnormal cells, called histiocytes, build up in various tissues of the body. Depending on the type and location of the disease, it can cause a range of symptoms, including bone pain, skin rashes, and organ dysfunction.

39. Histoplasmosis: Histoplasmosis is a fungal infection caused by inhaling spores of the Histoplasma fungus found in soil and bat or bird droppings. The infection can range from mild to severe and may affect the lungs or spread to other parts of the body.

40. HIV Infection: HIV (Human Immunodeficiency Virus) is a virus that attacks the body’s immune system, leading to acquired immunodeficiency syndrome (AIDS). HIV weakens the immune system, making it difficult for the body to fight off infections and diseases.

41. HIV/AIDS: HIV/AIDS refers to the progression of HIV infection to the advanced stage, where the immune system is severely damaged, and the person becomes susceptible to life-threatening infections and cancers.

42. Hives (Urticaria): Hives, also known as urticaria, are itchy, raised, and red welts that appear on the skin due to an allergic reaction or other triggers. They can be acute or chronic and may be caused by various factors.

43. Hodgkin Lymphoma: Hodgkin lymphoma is a type of cancer that originates in the lymphatic system, specifically in the white blood cells called lymphocytes. It is characterized by the presence of Reed-Sternberg cells and may cause swollen lymph nodes, fever, and weight loss.

44. Horner’s Syndrome: Horner’s syndrome is a group of symptoms caused by damage to the nerves in the eye and face. It can lead to a drooping eyelid, constricted pupil, and decreased sweating on one side of the face.

45. Human Papillomavirus (HPV): HPV is a group of viruses that can cause warts and is associated with various types of cancer, including cervical, anal, and genital cancers.

46. Huntington’s Disease: Huntington’s disease is a progressive genetic disorder that causes the breakdown of nerve cells in the brain, leading to cognitive, motor, and psychiatric symptoms.

47. Hydatidosis: Hydatidosis, also known as echinococcosis, is a parasitic infection caused by tapeworm larvae. The infection can affect various organs, most commonly the liver and lungs.

48. Hydrocele: Hydrocele is a condition where fluid accumulates around the testicle, leading to swelling in the scrotum.

49. Hydrocephalus: Hydrocephalus is a condition where there is an abnormal buildup of cerebrospinal fluid in the brain, leading to increased pressure and enlargement of the head in infants.

50. Hydrophobia (Rabies): Hydrophobia, commonly known as rabies, is a viral infection that affects the central nervous system and is transmitted through the bite of an infected animal. It can be fatal once symptoms appear.

51. Hyperacusis: Hyperacusis is a hearing disorder characterized by increased sensitivity to certain sounds, which can be painful or distressing.

52. Hypercalcemia: Hypercalcemia refers to higher than normal levels of calcium in the blood, which can lead to various symptoms, including fatigue, nausea, and bone pain.

53. Hyperemesis Gravidarum: Hyperemesis gravidarum is a severe form of morning sickness during pregnancy, characterized by persistent nausea, vomiting, and dehydration.

54. Hyperglycemia (High Blood Sugar): Hyperglycemia occurs when the blood sugar levels are higher than normal, often seen in people with diabetes.

55. Hyperhidrosis (Excessive Sweating): Hyperhidrosis is a condition characterized by excessive sweating, beyond what is necessary to regulate body temperature.

56. Hyperkalemia: Hyperkalemia is a condition where there is an abnormally high level of potassium in the blood, which can lead to heart rhythm disturbances.

57. Hyperlipidemia: Hyperlipidemia is a condition where there are elevated levels of lipids, such as cholesterol and triglycerides, in the blood, increasing the risk of heart disease.

58. Hyperopia (Farsightedness): Hyperopia, or farsightedness, is a common vision problem where distant objects can be seen more clearly than nearby objects.

59. Hyperparathyroidism: Hyperparathyroidism occurs when the parathyroid glands produce too much parathyroid hormone, leading to increased calcium levels in the blood.

60. Hypertension: Hypertension, or high blood pressure, is a condition where the force of blood against the artery walls is consistently too high, increasing the risk of heart disease and other health problems.

61. Hypertension (High Blood Pressure): Hypertension is another term used to describe high blood pressure.

62. Hyperthyroidism: Hyperthyroidism is a condition where the thyroid gland produces an excess of thyroid hormones, leading to symptoms such as weight loss, rapid heartbeat, and anxiety.

63. Hypertrophic Cardiomyopathy: Hypertrophic cardiomyopathy is a genetic heart condition where the heart muscle becomes abnormally thick, potentially affecting the heart’s ability to pump blood effectively.

64. Hypoactive Sexual Desire Disorder (HSDD): HSDD is a sexual desire disorder characterized by a lack of interest in sexual activity, causing distress or relationship problems.

65. Hypoglycemia (Low Blood Sugar): Hypoglycemia occurs when blood sugar levels drop below normal, leading to symptoms such as shakiness, dizziness, and confusion.

66. Hyponatremia: Hyponatremia is a condition where there is a low level of sodium in the blood, which can cause fluid imbalances and lead to various health issues.

67. Hypoparathyroidism: Hypoparathyroidism occurs when the parathyroid glands do not produce enough parathyroid hormone, leading to low calcium levels in the blood.

68. Hypopituitarism: Hypopituitarism is a condition where the pituitary gland fails to produce one or more of its hormones, causing various hormonal imbalances.

69. Hypotension: Hypotension, or low blood pressure, occurs when the force of blood against the artery walls is lower than normal, leading to symptoms such as dizziness and fainting.

70. Hypothyroid Myopathy: Hypothyroid myopathy is a muscle disorder that occurs due to untreated or poorly managed hypothyroidism.

71. Hypothyroidism: Hypothyroidism is a condition where the thyroid gland does not produce enough thyroid hormones, leading to various symptoms such as fatigue, weight gain, and sensitivity to cold.


I hope you found this article “Diseases That Start With H” helpful and got insights into some of the rare and lesser-known medical conditions.

Also, keep in mind that, this isn’t an exhaustive list, if there are any Diseases starting with the letter H.

Feel free to leave a comment below with the missing Disease and I’ll update the list as soon as possible.

And, if you’d like to explore more Diseases starting with different letters of the alphabet, click the link below:

  • Diseases That Start With I
  • Diseases That Start With J
  • Diseases That Start With K
  • Diseases That Start With L

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