In an overall lifestyle sense,  the fact that symptoms come and go leads to the victim having periods of weeks to years of being highly functional and productive,  interspersed with periods of being nonproductive and having a hard time getting anything done.  Life seems to progress in fits and starts. Great progress is made on projects which later get shelved for long periods. As the disease continues,  the productive periods become shorter,  fewer, and farther between.

 There are emotional changes in mercury poisoning.  Depression slowly sets in.  Victims feel fatigued and listless.  They lack motivation - even for crucial tasks.  They lose interest in their surroundings and in their own life.  They do not enjoy life,  or experience happiness or joy.  They experience constant fear e. g. of losing their job.  They may be very tense.  They feel hopeless.  They have a sense of impending doom.  Every small problem is discouraging.  Minor difficulties seem overwhelming and insurmountable.

 The altered emotional state of a mercury intoxicated person leads to impaired interpersonal relationships.  They become increasingly irritable and sensitive,  reacting strongly to relatively innocent remarks.  They may not be able to take orders,  instructions, or suggestions without losing their temper.  They resent criticism and may interpret innocent remarks critically.  They may have an exaggerated response to stimulation and become fearful or anxious and nervous.  They may project their fears and anxieties onto others,  making inappropriate criticisms or attacks.  They become shy and avoid dealing with strangers.  While timid,  they may unexpectedly lose self control with strangers.  They may wish to visit with friends and family extensively,  often wishing to engage in long,  repetitive conversations,  then withdraw for prolonged periods of time.  They withdraw more and more from social contacts.

 Intelligence gradually deteriorates.  Previously bright persons become dull and slow in thinking.  They suffer from a progressive decline specifically affecting short term memory as well as the faculties for logical reasoning.  Thus their ability to do things like balance the checkbook,  do math,  or play chess suffers.  They lose the ability to concentrate. Memory problems may be more from distractability and inability to concentrate and pay enough attention to get things INTO their memory than an actual failure to remember things (thus they may complain of memory problems but do well on memory tests).  They cease being motivated towards their work or other tasks.  Thoughts become heavy, repetitive and pedantic. Creative thinking becomes progressively more difficult,  eventually becoming impossible.  They become unable to select the right words to convey their meaning,  and make stylistic and grammatical errors.  Their ability to express themselves declines progressively.

 There is a distinctive cognitive symptom of being unable to think clearly without great effort.  The best description for people who have not experienced it is of a hangover without pain.  People who have experienced it will recognize the term "brain fog" as entirely descriptive.

 As the victim's level of intoxication waxes and wanes they go through periods of life when they do or do not dream.  Dreaming may be in black and white.

 Early physical symptoms include dizziness,  tinnitus (ringing in the ears), insomnia,  daytime drowsiness,  loss of appetite,  a tendency towards diarrhea - often alternating with constipation,  cold hands and feet,  a tendency towards sweating (some people have the opposite symptom and do not sweat at all), flushing or reddening of the skin - particularly on the face and neck. Some people blush frequently, but others do not blush at all.  Asthma is a symptom of chronic mercury poisoning.  Digestive disturbances are also common.

 The skin becomes dry,  athlete's foot and toenail fungus progress,  and the insides of the ankles, particularly behind the ankle bone and a bit above it become dry,  itchy,  flaky and peel.  This often becomes painful and annoying enough to keep the victim up at night.  Even after fungus and yeast infection has been eliminated hyperkeratosis,  often with papular erythema and itching are common.

 The hair becomes thinner,  dryer,  duller,  less strongly colored,  slower growing,  and more brittle.

 The biological clock is disturbed.  Waking up late and staying up late is more common than being an "early bird." Try as they might,  the mercury poisoned person simply cannot control their circadian rhythm.

 Victims may become photophobic and find bright light uncomfortable and unpleasant.  There may be visual disturbances,  including alterations in color perception leading to reduced sensitivity to the color red,  or color blindness.  The ability to focus on distant objects may be sporadically impaired. Peripheral vision may be reduced in the most severe cases.

 The hands and feet often become distinctly cold.  This can occur suddenly and is most distinctive when combined with sweating.  Later in more severe poisoning they may also tingle or lose feeling.

 The effects of mercury on the mouth are receding,  sometimes spongy gums that bleed easily and teeth that are 'loose' in their sockets and can be wiggled very slightly.  It also causes excessive salivation and unusually bad breath.

 Mercury interferes with the sense of smell which becomes less acute,  and later with hearing,  in which perception of sounds does not diminish as notably as the patient's ability to understand and interpret them - e. g. to understand speech directed at them even though they hear it clearly.

 Victims often experience discomfort that feels like a "tight band around their head."  They may also experience sharp points of discomfort in their ear canals at bedtime.

 Mercury also interferes with the body's ability to regulate temperature. Victims may alternate between being hot and cold when the temperature isn't changing,  or have to wear more clothes than other people,  or have more difficulty than other people in staying comfortable while the temperature changes.  Temperature disregulation also leads to 'night sweats.'