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Metabolic Acidosis Clinical Presentation

  • Author: Christie P Thomas, MBBS, FRCP, FASN, FAHA; Chief Editor: Vecihi Batuman, MD, FACP, FASN  more...
Updated: Dec 18, 2015


Symptoms of metabolic acidosis are not specific. The respiratory center in the brainstem is stimulated, and hyperventilation develops in an effort to compensate for the acidosis. As a result, patients may report varying degrees of dyspnea. Patients may also report chest pain, palpitations, headache, confusion, generalized weakness, and bone pain. Patients, especially children, also may present with nausea, vomiting, and decreased appetite.

The clinical history in metabolic acidosis is helpful in establishing the etiology when symptoms relate to the underlying disorder. The age of onset and a family history of acidosis may point to inherited disorders, which usually start during childhood. Important points in the history include the following:

  • Diarrhea - GI losses of HCO 3 -
  • History of diabetes mellitus, alcoholism, or prolonged starvation - Accumulation of ketoacids
  • Polyuria, increased thirst, epigastric pain, vomiting - Diabetic ketoacidosis (DKA)
  • Nocturia, polyuria, pruritus, and anorexia - Renal failure [6]
  • Ingestion of drugs or toxins - Salicylates, acetazolamide, cyclosporine, ethylene glycol, methanol
  • Visual symptoms, including dimming, photophobia, scotomata - Methanol ingestion
  • Renal stones - RTA or chronic diarrhea
  • Tinnitus, blurred vision, and vertigo - Salicylate overdose

Physical Examination

The best recognized sign of metabolic acidosis is Kussmaul respirations, a form of hyperventilation that serves to increase minute ventilatory volume. This is characterized by an increase in tidal volume rather than respiratory rate and is appreciated as deliberate, slow, deep breathing.

Chronic metabolic acidosis in children may be associated with stunted growth and rickets.

Coma and hypotension have been reported with acute severe metabolic acidosis.

Other physical signs of metabolic acidosis are not specific and depend on the underlying cause. Some examples include xerosis, scratch marks on the skin, pallor, drowsiness, fetor, asterixis, and pericardial rub for renal failure, as well as reduced skin turgor, dry mucous membranes, and fruity smell for DKA.

Contributor Information and Disclosures

Christie P Thomas, MBBS, FRCP, FASN, FAHA Professor, Department of Internal Medicine, Division of Nephrology, Departments of Pediatrics and Obstetrics and Gynecology, Medical Director, Kidney and Kidney/Pancreas Transplant Program, University of Iowa Hospitals and Clinics

Christie P Thomas, MBBS, FRCP, FASN, FAHA is a member of the following medical societies: American College of Physicians, American Heart Association, American Society of Nephrology, Royal College of Physicians

Disclosure: Nothing to disclose.


Khaled Hamawi, MD, MHA Director, Multi Organ Transplant Center, King Fahad Specialist Hospital, Dammam

Khaled Hamawi, MD, MHA is a member of the following medical societies: American Society of Transplantation, American Society of Nephrology

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Eleanor Lederer, MD, FASN Professor of Medicine, Chief, Nephrology Division, Director, Nephrology Training Program, Director, Metabolic Stone Clinic, Kidney Disease Program, University of Louisville School of Medicine; Consulting Staff, Louisville Veterans Affairs Hospital

Eleanor Lederer, MD, FASN is a member of the following medical societies: American Association for the Advancement of Science, International Society of Nephrology, American Society for Biochemistry and Molecular Biology, American Federation for Medical Research, American Society for Bone and Mineral Research, American Society of Nephrology, American Society of Transplantation, Kentucky Medical Association, National Kidney Foundation, Phi Beta Kappa

Disclosure: Received grant/research funds from Dept of Veterans Affairs for research; Received salary from American Society of Nephrology for asn council position; Received salary from University of Louisville for employment; Received salary from University of Louisville Physicians for employment; Received contract payment from American Physician Institute for Advanced Professional Studies, LLC for independent contractor; Received contract payment from Healthcare Quality Strategies, Inc for independent cont.

Chief Editor

Vecihi Batuman, MD, FACP, FASN Huberwald Professor of Medicine, Section of Nephrology-Hypertension, Tulane University School of Medicine; Chief, Renal Section, Southeast Louisiana Veterans Health Care System

Vecihi Batuman, MD, FACP, FASN is a member of the following medical societies: American College of Physicians, American Society of Hypertension, American Society of Nephrology, International Society of Nephrology

Disclosure: Nothing to disclose.

Additional Contributors

James W Lohr, MD Professor, Department of Internal Medicine, Division of Nephrology, Fellowship Program Director, University of Buffalo State University of New York School of Medicine and Biomedical Sciences

James W Lohr, MD is a member of the following medical societies: American College of Physicians, American Heart Association, American Society of Nephrology, Central Society for Clinical and Translational Research

Disclosure: Partner received salary from Alexion for employment.

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Table. Comparison of Types 1, 2, and 4 RTA
Characteristics Proximal (Type 2) Distal (Type 1) Type 4
Primary defect Proximal HCO3 - reabsorption Diminished distal H+ secretion Diminished ammoniagenesis
Urine pH < 5.5 when serum HCO3 - is low >5.5 < 5.5
Serum HCO3 - >15 mEq/L Can be < 10 mEq/L >15 mEq/L
Fractional excretion of HCO3 - (FEHCO3) >15-20% during HCO3 - load < 5% (can be as high as 10% in children) < 5%
Serum K+ Normal or mild decrease Mild-to-severe decrease* High
Associated features Fanconi syndrome ... Diabetes mellitus, renal insufficiency
Alkali therapy High doses Low doses Low doses
Complications Osteomalacia or rickets Nephrocalcinosis, nephrolithiasis ...
*K+ may be high if RTA is due to volume depletion.
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