Achalasia: Symptoms, Types, Causes and Treatment

Achalasia is a rare but impactful disease of the esophagus, disrupting the simple act of swallowing and often complicating daily life. Despite its rarity, its symptoms can be mistaken for other more common conditions—delaying diagnosis and effective care. Recent research has deepened our understanding of achalasia’s symptoms, types, causes, and treatments, offering hope and clarity to both patients and clinicians. In this comprehensive article, we’ll break down the latest evidence on achalasia, helping you recognize its signs, understand its origins, and explore modern management options.

Symptoms of Achalasia

When achalasia develops, the esophagus loses its ability to move food down into the stomach seamlessly. The result is a set of symptoms that might be subtle at first, but typically worsen over time. These symptoms can mimic other gastrointestinal or respiratory conditions, making early recognition a challenge for both individuals and healthcare providers.

Symptom	Description	Frequency/Prominence	Source(s)
Dysphagia	Difficulty swallowing solids/liquids	Most common, ~86%	1 2 3 4 5
Regurgitation	Return of undigested food or saliva	Frequent, ~79%	1 2 3 4 5
Chest pain	Chest discomfort, sometimes severe	Intermittent	2 3 4 5
Weight loss	Unintentional reduction in body weight	Present in some cases	2 4 5
Respiratory	Cough, aspiration, wheezing, hoarseness	Up to 40% of patients	3 4 9
Heartburn	Burning sensation in chest	Less common/atypical	1 9
Slow eating	Need to eat slowly, use unusual postures	Noted by 79% at time of diagnosis	1

Table 1: Key Symptoms

The Spectrum of Achalasia Symptoms

Achalasia symptoms can be both “typical” and “atypical,” varying in frequency and severity.

Classic Symptoms

• Dysphagia (Difficulty Swallowing):
  The hallmark of achalasia is dysphagia, affecting both solids and liquids. Most patients eventually report this symptom, though it may not be the first issue noticed. It can progress from occasional difficulty to persistent trouble, often leading to changes in eating habits 1 2 3 4 5.

• Regurgitation:
  Many patients experience the backflow of undigested food or saliva, particularly when lying down or bending over. This can be mistaken for reflux disease, sometimes delaying correct diagnosis 1 2 3 4 5.

• Chest Pain:
  Achalasia can cause intermittent or persistent chest pain, which may mimic heart disease or other esophageal disorders 2 3 4 5.

• Weight Loss:
  Difficulty eating and frequent regurgitation can result in unintentional weight loss over time, especially if the disease progresses without intervention 2 4 5.

Subtle and Atypical Symptoms

• Respiratory Complications:
  Chronic regurgitation can lead to aspiration—where food or fluid enters the airway—causing cough, wheezing, hoarseness, and even recurrent respiratory infections. In some studies, up to 40% of patients report at least one respiratory symptom daily 3 4 9.

• Heartburn:
  Some patients describe a burning sensation in the chest, which can be confused with acid reflux. However, in achalasia, this is usually due to retained food fermenting in the esophagus rather than true acid reflux 1 9.

• Slow Eating and Compensatory Behaviors:
  Patients may unconsciously adopt slow eating, avoid certain foods, or use physical maneuvers like arching the neck or standing straight to help food pass. These behaviors can be revealing clues for clinicians 1.

Evolution Over Time

Symptoms usually begin subtly and may increase in number and severity over several years. Importantly, the number or severity of symptoms does not always match how much the esophagus is affected on imaging tests 1. This means that some patients with severe symptoms may have only mild changes seen on radiological exams, and vice versa.

Types of Achalasia

As our understanding has grown, experts have classified achalasia into different types based on esophageal muscle behavior, especially with the advent of high-resolution manometry. This classification not only improves diagnosis but also guides treatment decisions and prognosis.

Type	Esophageal Pattern	Clinical Features	Source(s)
Type I	Minimal/no pressurization (classic)	Slow progression, less chest pain	2 4 7 8 11 17
Type II	Panesophageal pressurization	Best treatment response	2 4 7 8 17
Type III	Spastic/distal esophageal contractions	More chest pain, poor response	2 4 6 8 17 18

Table 2: Achalasia Subtypes

High-Resolution Manometry and Subtype Classification

High-resolution manometry (HRM) revolutionized how clinicians diagnose and classify achalasia. It measures pressures along the esophagus, identifying three main subtypes 2 4 7 8 17:

• Type I (Classic Achalasia):
  Characterized by minimal or no pressurization in the esophageal body and absent peristalsis. This form often develops gradually with less chest pain.

• Type II (With Compression):
  Shows panesophageal pressurization—meaning the entire esophagus contracts as one unit when swallowing. This subtype responds best to treatment, with higher symptom relief rates after interventions 2 4 8 18.

• Type III (Spastic Achalasia):
  Features spastic or premature contractions in the lower esophagus. Patients often experience more severe chest pain and are less likely to respond well to standard treatments. This type is also linked to a higher inflammatory response 6 8 18.

Why Subtype Matters

• Predicts Treatment Response:
  Type II patients generally have the best outcomes with therapies like pneumatic dilation or myotomy, while Type III often requires more aggressive or specialized intervention 8 18.

• Guides Therapy Choice:
  Knowing the subtype helps clinicians tailor therapy—such as choosing surgical myotomy for spastic forms 17 18.

• Prognosis:
  Subtype influences both short- and long-term symptom control and risk of recurrence 8 18.

Causes of Achalasia

Achalasia’s root cause has long puzzled researchers. Current evidence suggests it is a complex, multifactorial disease involving autoimmune, genetic, and possibly viral factors.

Proposed Cause	Mechanism	Evidence Strength	Source(s)
Autoimmunity	Immune attack on myenteric nerves	Strong	4 6 9 10 12 13
Genetics	Predisposition, familial clustering	Moderate	9 11 13
Viral infection	Trigger for immune response (e.g., HSV-1)	Moderate	6 9 10 13
Environmental	Unidentified triggers	Unclear	10 11 13
Secondary causes	Chagas disease, tumors	Well established	4 16

Table 3: Proposed Etiologies

Autoimmune Mechanisms

• Immune System Attack:
  The leading theory is that achalasia arises from an autoimmune process targeting the esophageal myenteric plexus, which controls muscle relaxation and peristalsis. This leads to the loss of inhibitory nerve cells and ultimately to the failure of the lower esophageal sphincter (LES) to relax 4 6 9 10 12 13.

• Supporting Evidence:

  • High prevalence of autoimmune markers and antibodies in patients 6 12.
  • Increased rates of other autoimmune diseases—such as type I diabetes, hypothyroidism, lupus, and Sjögren's syndrome—among achalasia patients 12.

Genetic Predisposition

• Familial Patterns:
  Occasional clustering in families, monozygotic twins, and associations with genetic syndromes (e.g., Allgrove syndrome, Down’s syndrome) suggest a hereditary component 9 11 13.

• Genetic Markers:
  Polymorphisms in genes related to nerve function and inflammation have been observed, but more research is needed to clarify these relationships 13.

Viral Triggers

• HSV-1 and Others:
  Some studies have implicated herpes simplex virus-1 (HSV-1) and possibly other viruses as triggers, initiating inflammation and subsequent autoimmune response in genetically susceptible individuals 6 9 10 13.

Environmental Factors

• Other Triggers:
  Environmental exposures may play a role, but no specific factor has been consistently identified 10 11 13.

Secondary Achalasia

• Chagas Disease:
  Caused by Trypanosoma cruzi infection, this mimics primary achalasia but is due to direct parasitic destruction of myenteric nerves 4 16.

• Tumors:
  Rarely, tumors at the gastroesophageal junction can cause similar symptoms by obstructing nerve function (pseudoachalasia) 4 16.

Treatment of Achalasia

While there is no cure that reverses the underlying nerve damage, several effective treatments are available to relieve symptoms by reducing lower esophageal sphincter pressure and improving esophageal emptying. Treatment choice depends on disease subtype, patient preference, age, and overall health.

Treatment	Description/Approach	Effectiveness / Suitability	Source(s)
Pneumatic Dilation	Endoscopic stretching of LES	High efficacy, repeatable	5 7 8 14 15 16 17
Surgical Myotomy	Cutting LES muscle (laparoscopic Heller)	Gold standard, durable relief	5 7 8 14 15 16 17
POEM	Peroral endoscopic myotomy	Minimally invasive, promising	5 7 8 15 16 17
Botulinum Toxin	Injection to relax LES	Temporary, bridge therapy	4 5 7 14 15 16 17
Medical Therapy	Nitrates, calcium channel blockers	Limited efficacy	4 5 15 17
Advanced/Salvage	Esophagectomy, feeding tube	For end-stage disease	4 16

Table 4: Treatment Options

Pneumatic Dilation

• How It Works:
  A balloon is inserted endoscopically and inflated at the LES, stretching and partially tearing the muscle to reduce pressure.

• Efficacy:
  Provides durable symptom relief for many, especially in type II achalasia. Repeat treatments may be needed. Comparative studies show it is as effective as surgical myotomy in many cases 8 14 15 16 17.

• Risks:
  Main risk is esophageal perforation, but this is relatively rare.

Surgical Myotomy (Heller Myotomy)

• How It Works:
  The LES muscle is cut laparoscopically, often with a partial fundoplication to prevent reflux.

• Efficacy:
  Considered the gold standard for long-term relief. Adding a fundoplication reduces risk of postoperative reflux 14.

• Suitability:
  Particularly beneficial for younger patients and those with type III achalasia 14 16 17.

Peroral Endoscopic Myotomy (POEM)

• How It Works:
  A minimally invasive endoscopic procedure that cuts the muscle from inside the esophagus.

• Benefits:
  Less invasive than surgery, promising results, especially for spastic/type III achalasia 5 8 15 16 17.

• Considerations:
  Requires specialized expertise; long-term outcomes are still being studied.

Botulinum Toxin Injection

• How It Works:
  Botox injected into the LES temporarily relaxes the muscle.

• Use Case:
  Provides short-term relief, often used for elderly or high-risk patients unable to undergo definitive therapy. Effects wear off within months, and repeated injections may become less effective 4 5 7 14.

Medical Therapy

• Medications:
  Nitrates and calcium channel blockers can reduce LES pressure, but usually offer only modest and short-lived benefit 4 5 15 17.

• Role:
  Reserved for patients who cannot undergo other interventions.

Advanced/Salvage Treatment

• End-stage Achalasia:
  In rare, severe cases with a massively dilated, non-functioning esophagus, surgical removal (esophagectomy) or placement of a feeding tube may be needed 4 16.

Treatment Selection and Follow-Up

• Factors Influencing Choice:

  • Achalasia subtype (especially Type III may benefit more from surgery/POEM) 8 18
  • Patient age and comorbidities
  • Center expertise and patient preference

• Follow-up:
  Ongoing monitoring is needed, as symptom recurrence can occur and interventions may need to be repeated 5 7 15 16 18.

• Cancer Risk:
  There is a small but recognized increase in the risk of esophageal cancer in achalasia patients, but no consensus on surveillance strategies exists 4 11 15 16.

Conclusion

Achalasia is a complex disease—challenging both to diagnose and manage. Yet, ongoing research and advances in diagnostic methods and therapy have greatly improved outcomes for patients worldwide.

Key Points:

• Symptoms often begin subtly, with dysphagia, regurgitation, and sometimes chest pain or respiratory issues being most common. Symptom severity does not always match findings on imaging.
• Types are now defined by high-resolution manometry, with three recognized subtypes (I, II, III) that guide treatment and predict outcomes.
• Causes involve a mix of autoimmune, genetic, and possibly viral factors, with the immune system attacking the esophageal nerves in genetically susceptible individuals.
• Treatment focuses on reducing LES pressure, with pneumatic dilation, surgical myotomy, and POEM as mainstays, alongside supportive options like botulinum toxin for those unfit for definitive therapy.

Early recognition, tailored intervention, and ongoing monitoring are critical for optimal patient outcomes. As research continues, future therapies may finally target the root causes, not just the symptoms, of this enigmatic disease.