Pseudohypoaldosteronism type 2 (Gordon syndrome): This condition is characterized by hypertension, hyperkalemia is not always present but can have low sodium levels due to the renal mechanism, and it can cause headaches and nausea due to the high blood pressure.

Primary Aldosteronism: Although typically associated with hypokalemia, some variants can present with low sodium levels. High blood pressure is a hallmark, and headaches and nausea can occur due to the hypertension.
Cushing's Syndrome: This condition can lead to hypertension and, in some cases, low sodium levels due to the mineralocorticoid effect of cortisol. Headaches and nausea are common symptoms.
Conn's Syndrome (Primary Aldosteronism) with renal impairment: In cases where renal function is compromised, the typical hypokalemia might not be present, and sodium levels could be low due to the kidney's inability to effectively manage electrolytes.

Pheochromocytoma: Although less common, this condition can cause episodic hypertension, headaches, and nausea. The electrolyte imbalance might not be directly related to the tumor but could be secondary to other mechanisms like renal impairment or fluid shifts.
Adrenal Crisis: This is a life-threatening condition that can present with hypotension or hypertension, electrolyte imbalances (including low sodium), and symptoms like headache and nausea. It's crucial to consider in patients with a history of adrenal insufficiency.
Subarachnoid Hemorrhage: While not directly causing low sodium, this condition can lead to the syndrome of inappropriate antidiuretic hormone secretion (SIADH), resulting in hyponatremia. High blood pressure and severe headache are typical presentations.

Liddle's Syndrome: A rare genetic disorder leading to excessive sodium absorption and potassium secretion in the kidneys, which can cause hypertension. However, the presentation with low sodium would be unusual and might be seen in specific circumstances like renal impairment.
Apparent Mineralocorticoid Excess: This is a rare condition that affects the metabolism of cortisol, leading to an excess of mineralocorticoid activity. It can cause hypertension and, in some cases, alterations in sodium levels, though typically it presents with hypokalemia.
17-alpha-hydroxylase deficiency: A rare congenital adrenal hyperplasia that can lead to hypertension due to the accumulation of mineralocorticoids and deficiency of sex hormones. Electrolyte imbalances, including low sodium, can occur due to the renal effects of these steroids.