Symptoms of Severe Hyponatremia (Sodium 122 mEq/L)
A patient with a serum sodium of 122 mEq/L will most likely present with moderate to severe neurological symptoms including nausea, vomiting, headache, confusion, weakness, and gait instability, with risk of progression to seizures or coma if untreated. 1
Symptom Severity Based on Sodium Level
At 122 mEq/L, this represents severe hyponatremia (defined as <125 mEq/L), which constitutes a medical emergency requiring urgent evaluation and treatment 2, 3:
Common Presenting Symptoms at This Level:
- Gastrointestinal symptoms: Nausea and vomiting are frequently the initial manifestations 1, 4
- Neurological impairment: Confusion, delirium, and altered mental status 1, 3
- Musculoskeletal symptoms: Muscle cramps, generalized weakness, and lethargy 1
- Balance disturbances: Gait instability, ataxia, and increased fall risk (21% vs 5% in normonatremic patients) 1, 5
- Headaches and dizziness 1, 6
Life-Threatening Symptoms (Requiring Immediate Intervention):
- Seizures (grand mal seizures possible) 1, 7, 6
- Coma or severely altered consciousness 1, 3
- Respiratory distress 1
- Risk of brain herniation and death in untreated cases 3
Critical Factors Affecting Symptom Presentation
The rapidity of onset determines symptom severity more than the absolute sodium value 3, 7:
- Acute hyponatremia (<48 hours duration): More severe symptoms, higher risk of cerebral edema and herniation 7
- Chronic hyponatremia (>48 hours duration): May be better tolerated with fewer acute symptoms, but still dangerous 7
Symptom Patterns by Patient Population
Approximately 64% of patients with severe hyponatremia present with neurological symptoms 4:
- Leading symptoms in hyponatremic patients: Nausea, falls, and weakness predominate 4
- Cognitive symptoms: Lack of concentration, forgetfulness, apathy 7
- Somnolence and disorientation can occur at this level 4
Clinical Significance and Mortality Risk
Even at 122 mEq/L, there is a 60-fold increased risk of hospital mortality (11.2% vs 0.19% in normonatremic patients) 1, 5. This level should never be dismissed as clinically insignificant, as it represents a true medical emergency requiring immediate treatment with hypertonic saline if severe symptoms are present 2, 8, 3.
Common Pitfall to Avoid
Do not wait for severe symptoms to develop before initiating treatment—symptoms can progress rapidly from mild confusion to seizures or coma, particularly in acute-onset hyponatremia 1, 3. The presence of any neurological symptoms at this sodium level warrants consideration of hypertonic saline administration 2, 8.