honeypot link
skip to main content
Professional
Consumer
Professional edition active
ENGLISH
MSD Manual
Professional Version
MEDICAL TOPICS
RESOURCES
COMMENTARY
PROCEDURES
QUIZZES
ABOUT US
MEDICAL TOPICS
RESOURCES
COMMENTARY
PROCEDURES
QUIZZES
Professional
/
Special Subjects
/
Special Subjects
Expand all
Collapse all
Care of the Surgical Patient
Preoperative Evaluation
History
Physical examination
Testing
General references
Procedural Risk Factors
Patient Risk Factors
Cardiac risk factors
History of ischemic stroke
Infections
Fluid and electrolyte imbalances
Nutritional disorders
Age
Patient risk factor references
More Information
Perioperative Management
Preoperative Medication and Comorbidity Management
Anticoagulants and antiplatelets
Corticosteroids
Other medications for chronic disorders
Diabetes
Heart disease
Pulmonary disease
Substance use
References
Preparation on Day of Surgery
Oral intake and bowel preparation
Preprocedural checklist
Preparation on day of surgery reference
Prevention of Surgical Site Infection
References
More Information
Postoperative Care
Airway and respiratory function
Fluids and hemodynamic status
Thromboembolism prophylaxis
Pain management
Mental status
Urinary retention and constipation
Wound care
Fever
Return to normal activity
Discharge precautions
References
Chronic Fatigue Syndrome
Chronic Fatigue Syndrome
References
Etiology
Symptoms and Signs
Diagnosis
Treatment
Treatment references
Prognosis
Key Points
More Information
Clinical Decision Making
Introduction to Clinical Decision Making
General reference
Evidence-Based Medicine and Clinical Guidelines
Evidence-Based Medicine
Formulating a clinical question
Gathering evidence to answer the question
Evaluating the quality and validity of the evidence
Deciding how to apply the evidence to the care of a given patient
Limitations of the evidence-based approach
Evidence-based medicine references
Clinical Guidelines
Clinical Decision-Making Strategies
Hypothesis Generation
Probability and odds
Hypothesis Testing
Hypothesis testing reference
Probability Estimations and the Testing Threshold
Probability Estimations and the Treatment Threshold
Limitations of quantitative decision methods
Cognitive Errors in Clinical Decision Making
Reference
Types of Cognitive Error
Availability error
Representation error
Premature closure
Anchoring errors
Confirmation bias
Attribution errors
Affective error
Risk Factors for Cognitive Error
Minimizing cognitive errors
Understanding Medical Tests and Test Results
Reference
Defining a Positive Test Result
Receiver operating characteristic (ROC) curves
Test Characteristics
Sensitivity, specificity, and predictive values
Likelihood ratios (LRs)
Dichotomous Tests
Pre-test probability
Continuous Tests
Bayes Theorem
Odds-likelihood calculation
Odds-likelihood nomogram
Tabular approach
Sequential Testing
Screening Tests
Multiple screening tests
Testing Thresholds
Economic Analyses in Clinical Decision Making
Cost
Marginal cost
Outcome
Quality-adjusted life year (QALY)
Number needed to treat
Clinically vs statistically significant outcome
Cost-Benefit Analysis
Marginal cost-effectiveness ratio
Electronic Health Records (EHR) and Clinical Decision Support
References
More Information
Dietary Supplements
Overview of Dietary Supplements
Definition
Labeling
Safety and Efficacy
Purity and Standardization
Other Concerns
More Information
Apoaequorin
Claims
Evidence
Adverse Effects
Drug Interactions
References
Ashwagandha
Claims
Evidence
Adverse Effects
Drug Interactions
References
Astragalus
Claims
Evidence
Adverse Effects
Drug Interactions
Reference
More Information
Bacopa
Claims
Evidence
Adverse Effects
Drug Interactions
References
Black Cohosh
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Cannabidiol (CBD)
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Chamomile
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Chondroitin Sulfate
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Chromium
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Coenzyme Q10 (CoQ10)
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Cranberry
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Creatine
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Dehydroepiandrosterone (DHEA)
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Echinacea
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Feverfew
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Fish Oil
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Garlic
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Ginger
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Ginkgo
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Ginseng
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Glucosamine
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Goldenseal
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Green Tea
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Holy Basil
Claims
Evidence
Adverse Effects
Drug Interactions
Intravenous Vitamin Therapy (Myers' Cocktail)
Claims
Evidence
Adverse Effects
Drug Interactions
References
Kava
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Licorice
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Melatonin
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Milk Thistle
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Reishi
Claims
Evidence
Adverse Effects
Drug Interactions
Reference
Rhodiola
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
S
-Adenosyl-L-Methionine
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Saw Palmetto
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
St. John’s Wort
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Valerian
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
Zinc Supplements
Claims
Evidence
Adverse Effects
Drug Interactions
References
More Information
The Dying Patient
The Dying Patient
General references
Communication and Clarification of Goals
Palliative Care and Hospice
Palliative care
Hospice
Palliative care and hospice reference
Advance Planning for Imminent Death
Financial Concerns and Disability
Legal and Ethical Concerns
Legal and ethical concerns references
Supporting Caregivers after Death
More Information
Symptom Relief for the Dying Patient
Pain
Opioid therapy
Other adjunctive therapies
Pain references
Dyspnea
Anorexia
Anorexia reference
Nausea and Vomiting
Constipation
Constipation reference
Pressure Injuries
Delirium and Confusion
Delirium and confusion reference
Frailty, Dementia, and Neuromuscular Diseases
Depression and Suicide
Depression and suicide reference
Stress and Grief
Exercise
Overview of Exercise
Overview reference
Pre-Exercise Medical Evaluation
Stretching and Flexibility
Stretching and flexibility references
Aerobic Exercise
Aerobic exercise references
Strength Training
Balance Training
Hydration
Exercise in Older Adults
Contraindications
Screening
Exercise program
References
General Principles of Medical Genetics
Overview of Genetics
Structure
Gene Function
Epigenetic factors
Traits and Inheritance Patterns
Construction of a family pedigree
Key Points
Single-Gene Defects
Autosomal Dominant
Autosomal Recessive
X-Linked Dominant
X-Linked Recessive
Factors Affecting Gene Expression
Penetrance and expressivity
Sex-limited inheritance
Genomic imprinting
Codominance
Chromosomal inactivation
Key Points
Multifactorial (Complex) Inheritance
DNA Variants and Mutations
Mutations and polymorphisms
Mosaicism
Extra or missing chromosomes
Uniparental disomy
Chromosomal translocation
Triplet repeat disorders (trinucleotide repeat disorders)
Anticipation
Key Points
Mitochondrial DNA Abnormalities
Key Points
Genetic Diagnostic Technologies
Clinical Uses of Genetics
Disease Understanding
Diagnosis
Genetic Screening
Treatment
Pharmacogenomics
Gene therapy
More Information
Key Points
Ethical Controversies in Genetics
Idiopathic Environmental Intolerance
Idiopathic Environmental Intolerance
General reference
Etiology
Triggers
Mechanism
Etiology reference
Symptoms and Signs
Diagnosis
Treatment
Treatment references
Key Points
Integrative, Complementary, and Alternative Medicine
Overview of Integrative, Complementary, and Alternative Medicine
Efficacy
Research
Safety
References
More Information
Types of Complementary and Alternative Medicine
Whole Medical Systems
Mind-Body Medicine
Biologically Based Practices
Manipulative and Body-Based Practices
Energy Medicine
Acupuncture
Evidence and Uses
Possible Adverse Effects and Contraindications
Reference
More Information
Ayurveda
Evidence for Ayurveda
Uses for Ayurveda
Possible Adverse Effects
References
Biofeedback
Uses for Biofeedback
References
Chelation Therapy
References
Chiropractic
Uses for Chiropractic
Possible Adverse Effects
References
Cupping
References
Diet Therapy
Intermittent Fasting
Ornish Diet
Macrobiotic Diet
Paleo Diet
References
Guided Imagery
Uses for Guided Imagery
References
Homeopathy
Regulation of Homeopathy
Evidence for Homeopathy
Uses of Homeopathy
Possible Adverse Effects
References
Hypnotherapy
Uses for Hypnotherapy
Reference
Magnets
Evidence and Uses
Possible Contraindications
References
Massage Therapy
References
Meditation
Uses for Meditation
References
Moxibustion
Reference
Naturopathy
Evidence for Naturopathy
References
Reflexology
References
Reiki
References
Relaxation Techniques
Reference
Scraping
References
Therapeutic Touch
References
Traditional Chinese Medicine
Evidence for Traditional Chinese Medicine
Possible Adverse Effects
References
Limb Prosthetics
Overview of Limb Prosthetics
Goals
Amputation rehabilitation team
Amputations
Preparing the patient
Postoperative management and complications
References
Prosthetic Components
Interface between the residual limb and prosthesis
Integrated suspension system
Structural components of a limb prosthesis
Cover and appearance of a limb prosthesis
Options for Limb Prostheses
Upper Extremity Prostheses
General types of upper extremity prosthesis
Partial-hand prostheses
Wrist disarticulation prostheses
Below-elbow prostheses
Elbow disarticulation and above-elbow prostheses
Shoulder disarticulation and interscapular/forequarter prostheses
Lower Extremity Prostheses
Partial-foot prostheses
Syme ankle disarticulation prostheses
Transtibial (below-knee) prostheses
Knee disarticulation and transfemoral (above-knee) prostheses
Hip disarticulation and hemipelvectomy prostheses
Preparing for a Limb Prosthesis
Preoperative Management
Postoperative and Preprosthetic Considerations
Preparatory prosthesis
Learning to use a limb prosthesis
Fitting the Prosthesis
Skin Care of the Residual Limb
Risk factors for skin problems
Skin breakdown
Skin infection
Other skin problems
Edema of the Residual Limb
Loosening of the Prosthesis
Pain in the Residual Limb
General reference
Etiology
Phantom limb pain
Phantom limb sensation
Persistent residual limb pain
Evaluation
Treatment
Transcutaneous osseointegration
Treatment reference
Medical Aspects of Travel
Air Travel
Barometric pressure changes
Children
Jet lag (circadian dysrhythmia)
Decreased oxygen tension
Low cabin humidity
Motion sickness
Pregnancy
Psychologic stress
Restricted mobility
Turbulence
Other issues
References
More Information
Foreign Travel
Vaccinations
COVID-19
Dengue
Influenza
Malaria
Schistosomiasis
Traveler’s diarrhea
Injury and death
Problems after returning home
More Information
Medicolegal Issues
Capacity (Competence) and Incapacity
Clinical capacity
Legal capacity
References
More Information
Informed Consent
References
Consent and Surrogate Decision Making
Children
Adults
Scope of patient choice
Reference
Advance Directives
Living will
Durable power of attorney for health care
Reference
Do-Not-Resuscitate (DNR) Orders and Portable Medical Orders
Portable Medical Orders
Confidentiality and HIPAA
Access to medical records
Notice of privacy practices
Limits on use of protected health information (PHI)
Marketing
Confidential communications
Complaints
Reference
More Information
Medical Malpractice
Nonspecific Symptoms
Fatigue
References
Etiology
Etiology references
Evaluation
History
Physical examination
Red flags
Interpretation of findings
Testing
Treatment
Treatment reference
Geriatrics Essentials
Key Points
Involuntary Weight Loss
References
Pathophysiology
Etiology
Evaluation
History
Physical examination
Red flags
Interpretation of findings
Testing
Evaluation references
Treatment
Treatment reference
Geriatrics Essentials
Key Points
Principles of Radiologic Imaging
Risks of Medical Radiation
Radiation and cancer
Radiation during pregnancy
Recommendations
References
Radiographic Contrast Agents and Contrast Reactions
Allergic-type contrast reactions
Contrast nephropathy
Lactic acidosis
Reference
Angiography
Uses of Angiography
Variations of Angiography
Digital subtraction angiography
Disadvantages of Angiography
Computed Tomography (CT)
Uses of CT
Variations of CT
Virtual colonoscopy and CT enterography
CT IV pyelography (CT IVP) or urography
CT angiography
Disadvantages of CT
Conventional Radiography
Uses of Conventional Radiography
Variations of Conventional Radiography
Contrast studies
Fluoroscopy
Disadvantages of Conventional Radiography
Magnetic Resonance Imaging
Uses of MRI
Contrast agents
Variations of MRI
Diffusion (diffusion-weighted) MRI
Echo planar imaging
Functional MRI
Gradient echo imaging
Magnetic resonance spectroscopy (MRS)
Magnetic resonance enterography
Perfusion MRI
Positron emission tomography (PET)–MRI
Disadvantages of MRI
Magnetic field
Claustrophobia
Contrast reactions
Reference
Mammography
Variations of mammography
Positron Emission Tomography (PET)
Uses of PET
Variations of PET
PET-CT
Disadvantages of PET
Radionuclide Scanning
Uses of Radionuclide Scanning
Variations of Radionuclide Scanning
Single-photon emission CT (SPECT)
Disadvantages of Radionuclide Scanning
Ultrasonography
Uses of Ultrasonography
Variations of Ultrasonography
A-mode
B-mode (gray-scale)
M-mode
Doppler
Disadvantages of Ultrasonography
Illicit Drugs and Intoxicants
Drug Testing
False results
Vaping
Ingredients
Complications of vaping
Reference
Injection Drug Use
Complications
Adulterants
Infectious agents
Diagnosis
Treatment
Body Packing and Body Stuffing
Body packing
Body stuffing
Diagnosis
Treatment
Alcohol Toxicity and Withdrawal
General reference
Pathophysiology
Chronic effects
Special populations
Pathophysiology reference
Symptoms and Signs
Acute effects
Toxicity or overdose
Chronic effects
Withdrawal
Diagnosis
Treatment
Toxicity or overdose
Withdrawal
Treatment reference
Alcohol Use Disorder and Rehabilitation
General reference
Etiology
Genetic factors
Symptoms and Signs
Diagnosis
Screening
Treatment
Maintenance
More Information
Wernicke Encephalopathy
Symptoms and Signs
Diagnosis
Prognosis
Treatment
Korsakoff Psychosis
Symptoms and Signs
Diagnosis
Treatment
Marchiafava-Bignami Disease
Amphetamines
Pathophysiology
Chronic effects
Symptoms and Signs
Acute effects
Toxicity or overdose
Chronic effects
Withdrawal
Diagnosis
Treatment
Toxicity or overdose
Withdrawal and rehabilitation
More Information
Methylenedioxymethamphetamine (MDMA)
Symptoms and Signs
Diagnosis
Treatment
More Information
Anabolic Steroids
Pathophysiology
Chronic effects
Symptoms and Signs
Diagnosis
Treatment
Prevention
More Information
Sedatives
Pathophysiology
Chronic effects
Pregnancy
Pathophysiology reference
Symptoms and Signs
Acute toxicity or overdose
Withdrawal
Diagnosis
Treatment
Toxicity or overdose
Withdrawal and detoxification
Treatment reference
More Information
Cannabinoids, Synthetic
Symptoms and Signs
Diagnosis
Treatment
Cathinones
Pathophysiology
Symptoms and Signs
Diagnosis
Treatment
Cocaine
General reference
Pathophysiology
Pregnancy
Symptoms and Signs
Acute effects
Toxicity or overdose
Chronic effects
Withdrawal
Diagnosis
Treatment
Toxicity or overdose
Abuse
More Information
Gamma Hydroxybutyrate
Symptoms and Signs
Diagnosis
Treatment
Hallucinogens
Pathophysiology
Symptoms and Signs
Chronic effects
Diagnosis
Treatment
More Information
Ketamine and Phencyclidine (PCP)
Symptoms and Signs
Diagnosis
Treatment
More Information
Marijuana (Cannabis)
Pathophysiology
Chronic effects
Symptoms and Signs
Acute effects
Chronic effects
Withdrawal
Symptoms and signs references
Diagnosis
Treatment
More Information
Opioid Toxicity and Withdrawal
Pathophysiology
Chronic effects
Pregnancy
Symptoms and Signs
Acute effects
Toxicity or overdose
Withdrawal
Diagnosis
Treatment
Toxicity or overdose
Withdrawal and detoxification
More Information
Opioid Use Disorder and Rehabilitation
Opioid use disorder
Treatment
Maintenance
Support
More Information
Other Commonly Abused Substances
Diuretics
Erythropoietin and Darbepoetin
Growth Hormone
Ipecac Syrup
Laxatives
More Information
Volatile Nitrites
Volatile Solvents
Symptoms and Signs
Acute effects
Chronic effects
Diagnosis
Treatment
More Information
Rehabilitation
Overview of Rehabilitation
Referral
Goals of therapy
Patient and caregiver issues
Geriatric Rehabilitation
Occupational Therapy (OT)
Evaluation
Interventions
Physical Therapy (PT)
Range of motion
Strength and conditioning
Proprioceptive neuromuscular facilitation
Coordination exercises
Ambulation exercises
Transfer training
Rehabilitative Measures for Treatment of Pain and Inflammation
Heat
Low-level laser therapy
Ultrasound
Cold
Electrical stimulation
Cervical traction
Massage
Acupuncture
Speech Therapy
Therapeutic and Assistive Devices
Cardiovascular Rehabilitation
Hip Surgery Rehabilitation
Leg Amputation Rehabilitation
Residual Limb Conditioning and Prostheses
Care of the residual limb and prosthesis
Complications
Stroke Rehabilitation
Hemiplegia
Ambulation problems
Spasticity
Spasticity reference
Hemianopia
Occupational therapy after stroke
Rehabilitation for Other Disorders
Arthritis
Blindness
Brain injury
Chronic pain
COPD (chronic obstructive pulmonary disease)
Critical illness polyneuropathy
Foot drop
Spinal cord injury
Sexuality
Overview of Sexuality
Sex and sexual identity
Societal attitudes about sex and sexuality
Masturbation
Homosexuality
Extramarital sex
Developmental aspects of sexuality
Role of the health care professional
References
Tobacco Use
Smoking and Other Tobacco Use
Epidemiology
Cigarettes
Other tobacco and nicotine products
Epidemiology references
Pathophysiology
Chronic effects of smoking
Secondhand smoke
Indirect effects of smoking
Pathophysiology references
Symptoms and Signs
Acute effects
Toxicity or overdose
Chronic effects
Withdrawal
Diagnosis
Treatment
Prevention
Prevention references
Key Points
More Information
Smoking Cessation
Reference
Nicotine Withdrawal
Interventions
Evidence-based counseling
Medications for smoking cessation
Medication safety
E-cigarettes and smoking cessation
Cessation in children
Cessation of non-cigarette tobacco products
Interventions references
Prognosis
Prognosis references
Key Points
More Information