APPEARANCE, HEALTH, physical state, BODY, LIFE-DEAD

Bite off more than you can chew

To take on a task that is way too big.

Black and blue

Badly bruised.

Black eye

Bruise around the eye.

Black out

Darken by turning off or dimming the lights; lose consciousness.

Blood, sweat & tears

Something that requires a lot of effort and hard work.

Elbow room

Enough space to move or work in.

Feeling under the weather

Feeling unwell.

Hit the sack (or sheets, or hay)

Go to bed.

Off colour

Unwell.

Snowed under

Having too much to do.

a sight for sore eyes (C1)

sb or sth that you are happy to see

beauty is in the eye of the beholder (C1)

the perception of beauty is subjective

don't judge a book by its cover (C1)

do not form opinion using appearance

not a hair out of place (C1)

have a very neat appearance

put years on somebody (C1)

cause to look or feel older

be thin on top (C2)

have lost some of the hair on your head

down at heel (C2)

having a poor, shabby appearance

grin/smile from ear to ear (C2)

smile widely

in your birthday suit (C2)

not wearing any clothes

somebody has a face like thunder (C2)

look extremely angry

cost an arm and a leg (B2)

be extremely expensive

foot the bill (B2)

pay for sth, esp. something expensive

nose around/about (B2)

look for sth, especially information about sb

pull somebody's leg (B2)

deceive someone playfully, tease someone

by the skin of one's teeth (C1)

by a very narrow margin, only just

elbow your way (C1)

make one's way through something

face the music (C1)

accept punishment for sth one has done

have sth on the brain (C1)

be always thinking about something

thumb a lift (C1)

hitchhike, ask for a ride

toe the line (C1)

follow orders, rules etc. strictly

back the wrong horse (C2)

support sb/sth that is not successful

catch sb's eye (C2)

be attractive enough to be noticed by sb

get sth off your chest (C2)

tell sb about sth that's been worrying you

hand it to somebody (C2)

admire someone for their skills

have a change of heart (C2)

a move to a different opinion or attitude

head a team (C2)

lead or be in charge of (a team, agency)

off/on the back of sth (C2)

as a result of an achievement or a success

poke one's nose into sth (C2)

get involved in sb else's private affairs

shoulder a responsibility (C2)

deal with or accept something difficult

a new lease of life (C1)

another chance to lead a happy life

be pushing up (the) daisies (C1)

be dead

from beyond the grave (C1)

after a person has died

live on the breadline (C1)

be extremely poor

look on the bright side (C1)

find good things in a bad situation

pay your last respects (C1)

honour someone after their death

take the bad with the good (C1)

accept all the features or parts of sth

be alive and well/kicking (C2)

continue to be popular or successful

be in the family way (C2)

be pregnant

life is not all beer and skittles (C2)

life is not always easy, enjoyable, or fun

as fit as a fiddle (B2)

be in very good health

be the picture of health (B2)

look very healthy

be green around the gills (C1)

look ill and pale

feel on top of the world (C1)

feel extremely happy and healthy

go under the knife (C1)

have a medical operation

look/feel like death warmed up (C1)

look or feel very ill

have one foot in the grave (C2)

be near death through old age or illness

kick the bucket (C2)

die

on the mend (C2)

improving in health or condition

prevention is better than cure (C2)

it's better to prevent sth than to cure it