A 52-year-old female patient presented with general weakness, headaches and occasional dizziness for the past three months.
She had also had occasional abdominal discomfort, moderate anorexia and weight loss due to nausea. Her mood was also low, she tired more easily than before and her skin and hair felt 'different'.
She was normally well, had a balanced diet and was not on regular medication. Her periods had stopped three years ago and menopausal symptoms had lessened since.
She seemed frustrated and concerned and had done some research into possible causes for her symptoms. She was unaware of any reason for anaemia and there was no family history of thyroid problems, but she indicated she would like these two possibilities ruled out.
Examination seemed unremarkable with a sitting BP of 124/74 mmHg, a regular pulse rate of 66, a BMI of 22kg/m2, no apparent goitre, normal looking - if a little pale - skin, and a normal abdominal examination.
There was no focal weakness in her limbs and the Romberg test was negative. The ear, nose and throat examination and a brief check of the cranial nerves were all normal. A urine dipstick was clear.
The challenge with such presentations is that the symptoms are vague and could be a feature of common temporary and self-resolving phases in patients with no clear underlying medical condition.
She has not had any investigations for more than 10 years and it appeared sensible to request FBC, ferritin, liver function, renal function, blood sugar, thyroid function and general inflammatory markers (CRP and ESR).
At the review the following week, the blood results were all normal apart from minimally out of range LFTs and slightly low sodium (133mmol/l) as well as mildly raised potassium levels of 5.3mmol/l.
However, a sitting-standing BP recheck confirmed a significant drop from 120/72mmHg to 92/60mmHg.
The BP finding determined postural hypotension, which is defined as a positional difference of at least 20mmHg.
In symptomatic patients this needs to be investigated further, although in the majority the cause of postural hypotension will be situational and harmless.
Typical causes are venous pooling after sitting, lying or standing for a long time or due to significant varicose veins, dehydration, side-effects of medication and the patient's personal constitution.
Patients may need advice on avoiding standing micturition or getting up too quickly from lying or sitting.
Occasionally those with postural hypotension and vaso-vagal syncopes will benefit from medication (prescribed by a specialist) including fludrocortisone (100-200 microgram at night), pyridostigmine or even paroxetine.
In some cases there can be an important underlying medical cause. In this patient the combination of symptoms and findings of some electrolyte disturbance supported the possibility of Addison's disease (adrenocortical insufficiency due to dysfunction of the adrenal cortex) or other endocrinological disorders.
She was referred for further investigations. For Addison's disease these can include more detailed blood tests, for example, adrenocorticotropic hormone (ACTH), cortisol and renin levels, adrenocortical antibodies (typical sign for autoimmune adrenalitis) and possibly a Synacthen test or a prolonged ACTH stimulation test. Indeed, her diagnosis of Addison's disease was confirmed within a few weeks.
Addison's disease is a rare condition with a prevalence of only about five per 100,000 in the UK. In the past TB was a likely leading cause for it, whereas now autoimmune adrenalitis accounts for more than 80 per cent of cases.
Other infections, medications, trauma or adrenal infiltration as part of other conditions, such as sarcoidosis, haemochromatosis or malignancy are possible but rare. Addison's disease is often difficult to detect in the early stages as the symptoms are notoriously unspecific and even blood parameters can remain almost normal for a long period of time.
In retrospect, this patient presented with many of the possible general features of Addison's disease. The postural hypotension was an important detail during the re-examination and should always be considered in patients with vague tiredness and 'dizziness'. Skin features such as hyperpigmentation or vitiligo in Addison's disease are not always clearly present.
With long-term steroid replacement the prognosis is generally good. Patients with Addison's disease have an increased chance of developing additional autoimmune conditions and they will need regular surveillance.
- Dr Jacobi is a salaried GP in York