Respiratory Acidosis: Symptoms, Diagnosis, and Treatment

By Dr. Deepak Bhasin in Pulmonology

Jan 22 , 2024 | 4 min read

What is Respiratory Acidosis? 

Respiratory acidosis is a medical condition characterised by a lower-than-normal blood pH due to an increase in acids within the bloodstream. This condition arises when the lungs are unable to effectively expel all the carbon dioxide (CO2) produced by the body. 

Maintaining a specific pH balance, typically ranging from 7.35 to 7.45 on the pH scale, is crucial for proper bodily function. The pH scale itself measures the level of acids and bases in the blood, extending from 0 (highly acidic) to 14 (highly basic or alkaline). The sudden onset of respiratory acidosis can be life-threatening.

Types of Respiratory Acidosis 

Respiratory acidosis is classified into two distinct types:

  • Acute respiratory acidosis: This type arises when carbon dioxide rapidly accumulates in the lungs.
  • Chronic respiratory acidosis: This form develops more gradually and is often due to long-term respiratory disorders. 

An individual can experience both types simultaneously. In cases where chronic respiratory acidosis is present, there may also be a concurrent development of a condition that leads to acute respiratory acidosis.

Symptoms of Respiratory Acidosis 

Early symptoms to watch out for include:

  • Breathlessness: Difficulty breathing, often accompanied by a feeling of tightness in the chest.
  • Anxiety: Persistent feelings of unease, worry, or fear.
  • Headache: A continuous or throbbing pain in the head, often affecting concentration.
  • Restlessness: Inability to stay still or find comfort, accompanied by a sense of agitation.
  • Blurred vision: Impaired eyesight, resulting in unclear or fuzzy images.
  • Confusion: Difficulty concentrating or understanding surroundings.

If these symptoms are ignored and the condition is left untreated, it can progress to more severe stages, leading to:

  • Lethargy: Extreme tiredness and lack of energy.
  • Sleepiness: Persistent drowsiness and a strong urge to sleep.
  • Coma: A state of deep unconsciousness.

Cardiorespiratory arrest: Cessation of both heart and lung function.

Causes of Respiratory Acidosis

Breathing problems are the primary cause of respiratory acidosis. But depending on the type, there might be different causes. 

Acute Respiratory Acidosis: Type II Respiratory Failure

Acute respiratory acidosis is characterised by a sudden surge of carbon dioxide in the lungs, termed type II respiratory failure. Several factors contribute to this condition:

  • Exacerbation of chronic obstructive pulmonary disease (COPD): Immediate worsening of Chronic obstructive pulmonary disease (COPD) leads to respiratory distress.
  • Acute severe asthma: Sudden and severe asthma attacks can result in elevated carbon dioxide levels.
  • Acute pulmonary edema: Swift accumulation of fluid in the lungs disrupts normal respiratory function.
  • Myasthenic crisis: A condition involving the severe weakness of muscles crucial for breathing.
  • Stroke with poor glasgow coma scale (GCS): Stroke-induced impairment in consciousness affects respiratory control.
  • Medications - overdose: Excessive intake of certain drugs can disturb the respiratory balance.
  • Guillain-Barré syndrome: Neurological disorder impacting peripheral nerves and respiratory muscles.

Chronic Respiratory Acidosis: Persistent Underlying Causes

Chronic respiratory acidosis develops gradually due to persistent underlying conditions:

  • Obesity: Restriction of lung movement from excess body weight contributes to chronic acidosis.
  • Longstanding COPD: Prolonged COPD leads to kidney failure and increased carbon dioxide.
  • Neuromuscular disorders: Neuromuscular disorders is a conditions affecting the nerves and muscles involved in breathing contribute to chronic acidosis.
  • End-stage pulmonary fibrosis: Advanced pulmonary fibrosis hampers normal respiratory function.
  • Obstructive sleep apnoea: Repeated interruptions in breathing during sleep contribute to chronic respiratory imbalances.
  • Central nervous system disorders affecting respiratory drive: Conditions impacting the central nervous system disrupt the control of respiratory function over time.

Respiratory Acidosis Diagnosis

A healthcare professional will inquire about symptoms and perform a physical examination to assess respiratory acidosis. To confirm the diagnosis, they may order several tests:

  • Arterial blood gas (ABG) test: This test evaluates the levels of carbon dioxide and oxygen in the blood.
  • Basic metabolic panel (BMP): The BMP analyses various substances in the body, helping to determine chemical balance and metabolic status.
  • Chest X-ray: An imaging procedure that produces a visual representation of the chest, including the lungs.
  • CO2 blood test: In this test, a small amount of blood is drawn using a thin needle from a vein in the arm to measure carbon dioxide levels in the blood.
  • CT scan: This diagnostic tool uses a series of X-rays to create a detailed 3D image of the lungs.
  • Electrolyte panel: This test measures the levels of specific electrolytes in the blood, which can vary in cases of respiratory acidosis.
  • Pulmonary function tests (PFTs): PFTs are used to evaluate the performance of the lungs.

Respiratory Acidosis Treatment 

The treatment of respiratory acidosis primarily focuses on addressing the underlying cause of the condition and restoring normal lung function. Here are some common approaches:

  • Improving ventilation: Treatment may include measures to enhance breathing and increase the removal of CO2 from the lungs. This can involve using bronchodilators, anti-inflammatory medications, or antibiotics if an infection is present.
  • Oxygen therapy: Administering supplemental oxygen can help if the blood oxygen level is low.
  • Ventilatory support: In severe cases, mechanical ventilation may be required to assist with breathing and improve gas exchange in the lungs.
  • Lifestyle modifications: Quitting smoking, maintaining a healthy weight, and engaging in respiratory therapies like pulmonary rehabilitation can be beneficial.


Respiratory acidosis is a critical condition marked by a lower-than-normal blood pH due to increased carbon dioxide in the blood. Timely diagnosis and effective treatment are essential for managing its symptoms and preventing complications. For comprehensive care and expert guidance on managing respiratory acidosis, consider consulting with the specialists at Max Healthcare, a renowned respiratory disorder hospital. Our dedicated team offers personalised treatment plans and state-of-the-art facilities to ensure the best possible outcomes for your health.