K64 — Haemorrhoids in ICD-10 and Why the Old Code Was I84

If the diagnosis field of your chart, discharge note or referral shows K64, it refers to haemorrhoids. This is a disease code, not an administrative note about the reason for a visit: a doctor recorded a specific condition. A separate source of confusion is that the same diagnosis can appear under two different codes — K64 and I84. Below we take the code apart, explain the I84 story, map the neighbouring categories and state plainly what the code does and does not say about your health.

What ICD-10 code K64 means

The official wording of K64 is «Haemorrhoids and perianal venous thrombosis». Element by element:

• K — the letter of ICD-10 Class XI: «Diseases of the digestive system», covering the oesophagus, stomach, intestines, liver, gallbladder, pancreas and the anorectal region.
• K64 — a category inside block K55–K64 («Other diseases of intestines»). It groups haemorrhoids proper together with a closely related condition: thrombosis of a superficial perianal vein.
• The digit after the dot — the detail: K64.0 first degree haemorrhoids; K64.1 second degree; K64.2 third degree; K64.3 fourth degree; K64.4 residual haemorrhoidal skin tags; K64.5 perianal venous thrombosis; K64.8 other specified haemorrhoids; K64.9 haemorrhoids, unspecified.

The degree (K64.0–K64.3) describes how internal cushions behave — from enlargement without prolapse to permanent prolapse that cannot be reduced. It is a description of anatomy seen on examination, not a ranking of how much you suffer.

A plain K64 with no digit simply means the degree was not specified during coding — a paperwork habit rather than a sign that the case is unusual.

Why older documents show I84 — the obsolete haemorrhoids code

This is the main source of confusion, so let us clear it up first. I84 and K64 are the same diagnosis from different editions of ICD-10.

Historically haemorrhoids belonged to Class IX — «Diseases of the circulatory system» (I00–I99), in the block on venous disease: the logic was vascular, since haemorrhoidal cushions are venous plexuses. Code I84 had its own subcategories: internal thrombosed, external without complication, residual skin tags and so on.

In ICD-10 updates adopted by WHO during the 2010s, category I84 was deleted, and haemorrhoids were moved to Class XI («Diseases of the digestive system») under the new code K64. The reason was not a medical reassessment but classification logic: the condition primarily concerns the anorectal region, and a dedicated subcategory for perianal venous thrombosis was added at the same time.

What this means in practice:

• I84 in an older document or in an export from a legacy system is the same haemorrhoids, not a different disease.
• K64 in a recent document is the current coding of that same diagnosis.
• Different codes in two of your certificates are not a contradiction and not a mistake, but two editions of the classification.
• There is no one-to-one mapping of subcategories: the old code split haemorrhoids into internal and external, the new one grades them by degree. The digit after the dot cannot be mechanically «translated» between them.

Where you may have seen this code

K64 appears in documents issued after contact with a doctor:

One nuance: a code on a referral is often provisional. It reflects a suspicion drawn from your complaints and may change after examination — to an anal fissure code, for instance, if the source of bleeding turns out to be different.

Is it dangerous or not

Let us put this plainly, without alarm and without playing it down. Haemorrhoids are not life-threatening and not an oncological disease. They are common, well studied and manageable in most cases. Seeing K64 in your chart implies neither surgery nor complications.

But there is a second half to the truth, and it matters more. Haemorrhoids are often diagnosed from the complaint «blood when passing stool» — and that complaint is not specific. Bright red blood on the paper or on the surface of the stool is indeed most often haemorrhoids or an anal fissure, yet the same symptom occurs with polyps, inflammatory bowel disease and tumours of the rectum and colon. A genuinely common mistake is to explain years of bleeding away as «my haemorrhoids» and never be examined.

What K64 does not tell you:

• whether haemorrhoids are truly the only source of the blood — an examination settles that, not a code;
• which degree applies, if no digit follows the dot;
• whether complications exist — a thrombosed cushion, or anaemia from prolonged blood loss.

What deserves calm but prompt attention: dark or black stool, mucus and blood mixed through the stool, a change in stool shape and rhythm, abdominal pain, unexplained weight loss, growing fatigue. Black tarry stool has nothing to do with haemorrhoids — it points to bleeding higher in the digestive tract; the shades and what they signal are covered in the guide on what stool colour means.

A separate case is K64.5, perianal venous thrombosis: sharp pain and a firm tender lump appearing within hours. It is not life-threatening, but it is exactly the situation where people are seen within days rather than «at some point».

Neighbouring codes and how they differ

Several categories around K64 are easy to mix up — they all concern the lower bowel and anus, yet they mean different things:

The table makes one practical point: similar symptoms belong to different codes, and only examination and endoscopy can tell them apart — not guesswork, and not the code in the header.

Which examinations are usually ordered

The scope is set by your doctor, based on age, symptoms and family history. It commonly includes:

• Proctological examination with a digital rectal exam — the basic first step in assessing any anorectal complaint.
• Anoscopy — inspection of the anal canal, where the cushions and their state are visible.
• Sigmoidoscopy or colonoscopy — when a source of bleeding above the haemorrhoidal cushions has to be excluded. Indications are a medical decision; how the preparation works is explained in the guide to preparing for a colonoscopy.
• Complete blood count — to avoid missing anaemia caused by prolonged blood loss.
• Faecal occult blood test — as a screening tool, not as a replacement for examination.

If you have symptoms but no clarity about which specialist to see and what to describe, it helps to assemble the picture in advance: when the bleeding started, its colour, whether it comes with pain, whether stool habits changed, and how long all of it has lasted. A structured account of symptoms does not replace a doctor, but it makes the appointment concrete and cuts down on follow-up visits.

What to do next

A sensible sequence once you see K64 in your documents:

1. Check whether a digit follows the dot. K64.5 (perianal venous thrombosis) and K64.3 (fourth degree) are different situations with different management.
2. Do not be puzzled by I84 in older paperwork — it is the same diagnosis under the previous edition of the classification.
3. Make sure the source of bleeding was established by examination, not assumed. This is the key point: «haemorrhoids» should not be diagnosed remotely from a single complaint.
4. Discuss whether endoscopy is warranted, especially after 45, with changed stool habits or a family history — the symptoms that make this conversation mandatory are described in the guide to colorectal cancer.
5. Review accompanying digestive symptoms: pain, heartburn and heaviness after meals are coded separately — for example K29 for gastritis and duodenitis.
6. Treatment decisions belong to your doctor, made in person with your documents at hand. The choice between observation, a minimally invasive procedure and surgery depends on the degree, not on the mere presence of the code.

The short version

K64 belongs to the digestive-diseases class and means haemorrhoids and perianal venous thrombosis. In the former ICD-10 edition the same diagnosis was coded I84 within the circulatory-diseases class, which is why older records still show it. The condition is not life-threatening, but the code does not confirm that rectal bleeding comes from it: examination does, and endoscopy where indicated. The decisions that follow belong to the doctor who sees you and your full record.