Chuveiro vs. duche vs. ducha
While chuveiro, duche, and ducha all relate to the concept of a shower, the difference lies primarily in regional usage between Brazil and Portugal, as well as specific technical distinctions regarding water heating and pressure.
Chuveiro
A2This is the most general term for the device itself. In Brazil, chuveiro usually refers to an electric shower head, which is the standard appliance in most homes. In Portugal, it specifically refers to the shower head (the nozzle) or the fixture.
O chuveiro queimou e agora só sai água fria.
(The shower burned out and now only cold water comes out.)
Preciso limpar os buracos do chuveiro que estão entupidos.
(I need to clean the showerhead holes that are clogged.)
No Brasil, é muito comum ter um chuveiro elétrico no banheiro.
(In Brazil, it is very common to have an electric shower in the bathroom.)
A altura do chuveiro pode ser ajustada.
(The height of the showerhead can be adjusted.)
Duche
A2This word is used almost exclusively in European Portuguese (Portugal). It refers to both the shower stall and the act of taking a shower. Brazilians rarely use duche in everyday conversation.
Vou tomar um duche rápido antes de sair.
(I am going to take a quick shower before heading out.)
A cabine de duche é feita de vidro temperado.
(The shower stall is made of tempered glass.)
Depois do treino, um duche quente sabe bem.
(After training, a hot shower feels good.)
O gel de duche acabou ontem à noite.
(The shower gel ran out last night.)
Ducha
B1In Brazil, ducha often distinguishes a high-pressure shower (usually heated by gas or solar energy) from the standard electric chuveiro. It also refers to cold showers found at pools or beaches, and the handheld sprayer next to a toilet (ducha higiênica).
A ducha da piscina é ótima para tirar a areia do corpo.
(The pool shower is great for getting the sand off your body.)
Neste hotel a água sai com força porque é uma ducha.
(In this hotel the water comes out with force because it is a high-pressure shower.)
Instalamos uma ducha higiênica ao lado do vaso sanitário.
(We installed a bidet sprayer next to the toilet.)
Prefiro banho de ducha a banho de banheira.
(I prefer taking a shower over taking a bath.)
Summary
In summary, use chuveiro for the physical device in both regions, but specifically for electric showers in Brazil. Use duche when speaking European Portuguese regarding the act or place of showering. Use ducha in Brazil when referring to high-pressure non-electric showers, outdoor showers, or handheld sprayers.